效果預覽
按下右側的“點擊預覽”按鈕可以在當前頁面預覽,點擊鏈接可以全屏預覽。
https://codepen.io/comehope/pen/dwzRyQ
可交互視頻
此視頻是可以交互的,你可以隨時暫停視頻,編輯視頻中的代碼。
請用 chrome, safari, edge 打開觀看。
第 1 部分:
https://scrimba.com/p/pEgDAM/ca6wWSk
第 2 部分:
https://scrimba.com/p/pEgDAM/c7Zy2AZ
第 3 部分:
https://scrimba.com/p/pEgDAM/c9R2Gsy
源代碼下載
每日前端實戰系列的全部源代碼請從 github 下載:
https://github.com/comehope/front-end-daily-challenges
代碼解讀
本項目可以訓練加、減、乘、除四則運算。比如訓練加法時,界面給出 2 個數值表示 2 個加數,小朋友心算出結果後大聲說出,然後點擊“?”按鈕查看結果,根據對照的結果,如果計算正確(或錯誤),就點擊綠勾(或紅叉),然後再開始下一道測驗。界面中還會顯示已經做過幾道題,正確率是多少。爲了增強趣味性,加入了音效,答對時會響起小貓甜美的叫聲,答錯時響起的是小貓失望的叫聲。
頁面用純 css 佈局,程序邏輯用 vue 框架編寫,用 howler.js 庫播放音效。整個應用分成 4 個步驟實現:靜態頁面佈局、加法的程序邏輯、四則運算的程序邏輯、音效處理。
一、頁面佈局
先創建 dom 結構,整個文檔分成 4 部分,.choose-type
是一組多選一按鈕,用於選擇四則運算的類型,.score
是成績統計數據,.expression
是一個算式,它也是遊戲的主體部分,.judgment
用於判斷答題是否正確:
<div id="app">
<div class="choose-type"></div>
<div class="score"></div>
<div class="expression"></div>
<div class="judgment"></div>
</div>
.choose-type
一共包含 4 個 input[type=radio]
控件,命名爲 arithmetic-type
,加、減、乘、除 4 種運算類型的值分別爲 1、2、3、4,每個控件後跟隨一個對應的label
,最終我們將把 input
控件隱藏起來,而讓用戶操作 label
。
<div id="app">
<div class="choose-type">
<div class="choose-type">
<input type="radio" id="addition" name="arithmetic-type" value="1">
<label for="addition">addition</label>
<input type="radio" id="subtraction" name="arithmetic-type" value="2">
<label for="subtraction">subtraction</label>
<input type="radio" id="multiplication" name="arithmetic-type" value="3">
<label for="multiplication">multiplication</label>
<input type="radio" id="division" name="arithmetic-type" value="4">
<label for="division">division</label>
</div>
<!-- 略 -->
</div>
.score
包含 2 個數據,一個是已經做過的題目數,一個是正確率:
<div id="app">
<!-- 略 -->
<div class="score">
<span>ROUND 15</span>
<span>SCORE 88%</span>
</div>
<!-- 略 -->
</div>
.expression
把一個表達式的各部分拆開,以便能修飾表達式各部分的樣式。.number
表示等式左邊的 2 個運算數,.operation
表示運算符和等號,.show
是一個問號,同時它也是一個按鈕,當心算出結果後,點擊它,就顯示出 .result
元素,展示運算結果:
<div id="app">
<!-- 略 -->
<div class="expression">
<span class="number">10</span>
<span class="operation">+</span>
<span class="number">20</span>
<span class="operation">=</span>
<span class="button show">?</span>
<span class="result">30</span>
</div>
<!-- 略 -->
</div>
.judgment
包含 2 個按鈕,分別是表示正確的綠勾和表示錯誤的紅叉,顯示在結果的下方:
<div id="app">
<!-- 略 -->
<div class="judgment">
<span class="button right">✔</span>
<span class="button wrong">✘</span>
</div>
</div>
至此,完整的 dom 結構如下:
<div id="app">
<div class="choose-type">
<input type="radio" id="addition" name="arithmetic-type" value="1">
<label for="addition">addition</label>
<input type="radio" id="subtraction" name="arithmetic-type" value="2">
<label for="subtraction">subtraction</label>
<input type="radio" id="multiplication" name="arithmetic-type" value="3">
<label for="multiplication">multiplication</label>
<input type="radio" id="division" name="arithmetic-type" value="4">
<label for="division">division</label>
</div>
<div class="score">
<span>ROUND 15</span>
<span>SCORE 88%</span>
</div>
<div class="expression">
<span class="number">10</span>
<span class="operation">+</span>
<span class="number">20</span>
<span class="operation">=</span>
<span class="button show">?</span>
<span class="result">30</span>
</div>
<div class="judgment">
<span class="button right">✔</span>
<span class="button wrong">✘</span>
</div>
</div>
接下來用 css 佈局。
居中顯示:
body{
margin: 0;
height: 100vh;
display: flex;
align-items: center;
justify-content: center;
background: linear-gradient(lightyellow, tan);
}
設置應用的容器樣式,黑色漸變背景,子元素縱向排列,尺寸用相對單位 vw
和 em
,以便在窗口縮放後能自適應新窗口尺寸:
#app {
width: 66vmin;
display: flex;
flex-direction: column;
align-items: center;
box-shadow: 0 1em 4em rgba(0, 0, 0, 0.5);
border-radius: 2em;
padding: 8em 5em;
background: linear-gradient(black, dimgray, black);
font-family: sans-serif;
font-size: 1vw;
user-select: none;
}
佈局 .choose-type
區域。隱藏 input
控件,設置 label
爲天藍色:
.choose-type input[name=arithmetic-type] {
position: absolute;
visibility: hidden;
}
.choose-type label {
font-size: 2.5em;
color: skyblue;
margin: 0.3em;
letter-spacing: 0.02em;
}
在 label
之間加入分隔線:
.choose-type label {
position: relative;
}
.choose-type label:not(:first-of-type)::before {
content: '|';
position: absolute;
color: skyblue;
left: -0.5em;
filter: opacity(0.6);
}
設置 label
在鼠標懸停時變色,當 input
控件被選中時對應的 label
會變色、首字母變大寫並顯示下劃線,爲了使視覺效果切換平滑,設置了緩動時間。這裏沒有使用 text-decoration: underline
設置下劃線,是因爲用 border
纔有緩動效果:
.choose-type label {
transition: 0.3s;
}
.choose-type label:hover {
color: deepskyblue;
cursor: pointer;
}
.choose-type input[name=arithmetic-type]:checked + label {
text-transform: capitalize;
color: deepskyblue;
border-style: solid;
border-width: 0 0 0.1em 0;
}
.score
區域用銀色字,2 組數據之間留出一些間隔:
.score{
font-size: 2em;
color: silver;
margin: 1em 0 2em 0;
width: 45%;
display: flex;
justify-content: space-between;
}
.expression
區域用大字號,各元素用不同的顏色區分:
.expression {
font-size: 12em;
display: flex;
align-items: center;
}
.expression span {
margin: 0 0.05em;
}
.expression .number{
color: orange;
}
.expression .operation{
color: skyblue;
}
.expression .result{
color: gold;
}
.show
是等號右邊的問號,它同時也是一個按鈕,在這裏把按鈕的樣式 .button
獨立出來,因爲後面還會用到 .button
樣式:
.expression .show {
color: skyblue;
font-size: 0.8em;
line-height: 1em;
width: 1.5em;
text-align: center;
}
.button {
background-color: #222;
border: 1px solid #555;
padding: 0.1em;
}
.button:hover {
background-color: #333;
cursor: pointer;
}
.button:active {
background-color: #222;
}
設置 .judgment
區域 2 個按鈕的樣式,它們還共享了 .button
樣式:
.judgment {
font-size: 8em;
align-self: flex-end;
}
.judgment .wrong {
color: orangered;
}
.judgment .right {
color: lightgreen;
}
至此,靜態頁面佈局完成,完整的 css 代碼如下:
body{
margin: 0;
height: 100vh;
display: flex;
align-items: center;
justify-content: center;
background: linear-gradient(lightyellow, tan);
}
#app {
width: 66vw;
display: flex;
flex-direction: column;
align-items: center;
box-shadow: 0 1em 4em rgba(0, 0, 0, 0.5);
border-radius: 2em;
padding: 8em 5em;
background: linear-gradient(black, dimgray, black);
font-family: sans-serif;
font-size: 1vw;
user-select: none;
}
.choose-type input[name=arithmetic-type] {
position: absolute;
visibility: hidden;
}
.choose-type label {
font-size: 2.5em;
color: skyblue;
margin: 0.3em;
letter-spacing: 0.02em;
position: relative;
transition: 0.3s;
}
.choose-type label:not(:first-of-type)::before {
content: '|';
position: absolute;
color: skyblue;
left: -0.5em;
filter: opacity(0.6);
}
.choose-type label:hover {
color: deepskyblue;
cursor: pointer;
}
.choose-type input[name=arithmetic-type]:checked + label {
text-transform: capitalize;
color: deepskyblue;
border-style: solid;
border-width: 0 0 0.1em 0;
}
.score{
font-size: 2em;
color: silver;
margin: 1em 0 2em 0;
width: 45%;
display: flex;
justify-content: space-between;
}
.expression {
font-size: 12em;
display: flex;
align-items: center;
}
.expression span {
margin: 0 0.05em;
}
.expression .number{
color: orange;
}
.expression .operation{
color: skyblue;
}
.expression .result{
color: gold;
}
.expression .show {
color: skyblue;
font-size: 0.8em;
line-height: 1em;
width: 1.5em;
text-align: center;
}
.judgment {
font-size: 8em;
align-self: flex-end;
}
.judgment .wrong {
color: orangered;
}
.judgment .right {
color: lightgreen;
}
.button {
background-color: #222;
border: 1px solid #555;
padding: 0.1em;
}
.button:hover {
background-color: #333;
cursor: pointer;
}
.button:active {
background-color: #222;
}
二、加法的程序邏輯
我們先用加法把流程跑通,再把加法擴展爲四則運算。
引入 vue 框架:
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.21/vue.min.js"></script>
創建一個 Vue 對象:
let vm = new Vue({
el: '#app',
})
定義數據,round
存儲題目數,round.all
表示總共答過了多少道題,round.right
表示答對了多少道題;numbers
數組包含 2 個元素,用於存儲等式左邊的 2 個運算數,用數組是爲了便於後面使用解構語法:
let vm = new Vue({
///...略
data: {
round: {all: 0, right: 0},
numbers: [0, 0],
}
///...略
})
定義計算屬性,operation
是操作符,目前是加號,result
是計算結果,等於 2 個運算數相加,score
是正確率,開始做第一題時正確率顯示爲 100%,後續根據實際答對的題數計算正確率:
let vm = new Vue({
///...略
computed: {
operation: function() {
return '+'
},
result: function() {
return this.numbers[0] + this.numbers[1]
},
score: function() {
return this.round.all == 1
? 100
: Math.round(this.round.right / (this.round.all - 1) * 100)
}
},
///...略
})
把數據綁定到 html 模板中:
<div id="app">
<!-- 略 -->
<div class="score">
<span>ROUND {{round.all - 1}}</span>
<span>SCORE {{score}}%</span>
</div>
<div class="expression">
<span class="number">{{numbers[0]}}</span>
<span class="operation">{{operation}}</span>
<span class="number">{{numbers[1]}}</span>
<span class="operation">=</span>
<span class="button show">?</span>
<span class="result">{{result}}</span>
</div>
<!-- 略 -->
</div>
至此,頁面中的數據都是動態獲取的了。
等式右邊的問號和結果不應同時顯示出來,在用戶思考時應顯示問號,思考結束後應隱藏問號顯示結果。爲此,增加一個 isThinking
變量,用於標誌用戶所處的狀態,默認爲 true
,即進入遊戲時,用戶開始思考第 1 道題目:
let vm = new Vue({
///...略
data: {
round: {all: 0, right: 0},
numbers: [0, 0],
isThinking: true,
},
///...略
})
把 isThinking
綁定到 html 模板中,用戶思考時只顯示問號 .show
,否則顯示結果 .result
和判斷結果正確與否的按鈕 .judgment
,此處請注意,對於佔據同一個視覺位置的元素,用 v-show=false
,即 display: none
隱藏,對於佔據獨立視覺位置的元素,用 visibility: hidden
隱藏:
<div id="app">
<!-- 略 -->
<div class="expression">
<!-- 略 -->
<span class="button show" v-show="isThinking">?</span>
<span class="result" v-show="!isThinking">{{result}}</span>
</div>
<div class="judgment" :style="{visibility: isThinking ? 'hidden' : 'visible'}">
<!-- 略 -->
</div>
</div>
接下來生成隨機運算數。創建一個 next()
方法用於開始下一個題目,那麼在頁面載入後就應執行這個方法初始化第 1 道題目:
let vm = new Vue({
///...略
methods: {
next: function() {
},
},
})
window.onload = vm.next
next()
方法一方面要負責初始化運算數,還要把答過的題目數加1,這裏獨立出來一個 newRound()
方法是爲了方便後面複用它:
let vm = new Vue({
///...略
methods: {
newRound: function() {
this.numbers = this.getNumbers()
this.isThinking = true
},
next: function() {
this.newRound()
this.round.all++
},
},
})
getNumbers()
方法用於生成 2 個隨機數,它調用 getRandomNumber()
方法來生成一個隨機數,其中 level
參數表示隨機數的取值範圍,level
爲 1 時,生成的隨機數介於 1 ~ 9 之間,level
爲 2 時,生成的隨機數介於 10 ~ 99 之間。爲了增加一點加法的難度,我們把 level
設置爲 2:
let vm = new Vue({
///...略
methods: {
getRandomNumber: function(level) {
let min = Math.pow(10, level - 1)
let max = Math.pow(10, level)
return min + Math.floor(Math.random() * (max - min))
},
getNumbers: function() {
let level = 2
let a = this.getRandomNumber(level)
let b = this.getRandomNumber(level)
return [a, b]
},
newRound: function() {
this.numbers = this.getNumbers()
this.isThinking = true
},
next: function() {
this.newRound()
this.round.all++
},
},
})
此時,每刷新一次頁面,運算數就會跟着刷新,因爲每次頁面加載都會運行 vm.next()
方法生成新的隨機數。
接下來我們來處理按鈕事件,頁面中一共有 3 個按鈕:問號按鈕 .show
被點擊後應顯示結果;綠勾按鈕 .right
被點擊後應給答對題的數目加 1,然後進入下一道題;紅叉按鈕 .wrong
被點擊後直接進入下一道題,所以我們在程序中增加 3 個方法,getResult()
、answerRight()
、answerWrong
分別對應上面的 3 個點擊事件:
let vm = new Vue({
///...略
methods: {
///...略
getResult: function() {
this.isThinking = false
},
answerRight: function() {
this.round.right++
this.next()
},
answerWrong: function() {
this.next()
},
},
})
把事件綁定到 html 模板:
<div id="app">
<!-- 略 -->
<div class="expression">
<!-- 略 -->
<span class="button show" v-show="isThinking" @click="getResult">?</span>
<!-- 略 -->
</div>
<div class="judgment" :style="{visibility: isThinking ? 'hidden' : 'visible'}">
<span class="button right" @click="answerRight">✔</span>
<span class="button wrong" @click="answerWrong">✘</span>
</div>
</div>
至此,加法程序就全部完成了,可以一道又一道題一直做下去。
此時的 html 代碼如下:
<div id="app">
<div class="choose-type">
<!-- 沒有改變 -->
</div>
<div class="score">
<span>ROUND {{round.all - 1}}</span>
<span>SCORE {{score}}%</span>
</div>
<div class="expression">
<span class="number">{{numbers[0]}}</span>
<span class="operation">{{operation}}</span>
<span class="number">{{numbers[1]}}</span>
<span class="operation">=</span>
<span class="button show" v-show="isThinking" @click="getResult">?</span>
<span class="result" v-show="!isThinking">{{result}}</span>
</div>
<div class="judgment" :style="{visibility: isThinking ? 'hidden' : 'visible'}">
<span class="button right" @click="answerRight">✔</span>
<span class="button wrong" @click="answerWrong">✘</span>
</div>
</div>
此時的 javascript 代碼如下:
let vm = new Vue({
el: '#app',
data: {
round: {all: 0, right: 0},
numbers: [0, 0],
isThinking: true,
},
computed: {
operation: function() {
return '+'
},
result: function() {
return this.numbers[0] + this.numbers[1]
},
score: function() {
return this.round.all == 1
? 100
: Math.round(this.round.right / (this.round.all - 1) * 100)
}
},
methods: {
getRandomNumber: function(level) {
let min = Math.pow(10, level - 1)
let max = Math.pow(10, level)
return min + Math.floor(Math.random() * (max - min))
},
getNumbers: function() {
let level = 2
let a = this.getRandomNumber(level)
let b = this.getRandomNumber(level)
return [a, b]
},
newRound: function() {
this.numbers = this.getNumbers()
this.isThinking = true
},
next: function() {
this.newRound()
this.round.all++
},
getResult: function() {
this.isThinking = false
},
answerRight: function() {
this.round.right++
this.next()
},
answerWrong: function() {
this.next()
},
},
})
window.onload = vm.next
三、四則運算的程序邏輯
我們先來評估一下四種運算在這個程序裏會在哪些方面有差異。首先,運算符不同,加、減、乘、除的運算符分別是“+”、“-”、“×”、“÷”;第二是運算函數不同,這個不用多說。根據這 2 點,我們定義一個枚舉對象 ARITHMETIC_TYPE
,用它存儲四種運算的差異,每個枚舉對象有 2 個屬性,operation
代表操作符,f()
函數是運算邏輯。另外,我們再聲明一個變量 arithmeticType
,用於存儲用戶當前選擇的運算類型:
let vm = new Vue({
///...略
data: {
///...略
ARITHMETIC_TYPE: {
ADDITION: 1,
SUBTRACTION: 2,
MULTIPLICATION: 3,
DIVISION: 4,
properties: {
1: {operation: '+', f: ([x, y]) => x + y},
2: {operation: '-', f: ([x, y]) => x - y},
3: {operation: '×', f: ([x, y]) => x * y},
4: {operation: '÷', f: ([x, y]) => x / y}
}
},
arithmeticType: 1,
},
})
改造計算屬性中關於運算符和計算結果的函數:
let vm = new Vue({
///...略
computed: {
///...略
operation: function() {
// return '+'
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].operation
},
result: function() {
// return this.numbers[0] + this.numbers[1]
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].f(this.numbers)
},
///...略
},
})
因爲上面 2 個計算屬性都用到了 arithmeticType
變量,所以當用戶選擇運算類型時,這 2 個計算屬性的值會自動更新。另外,爲了讓 ui 邏輯更嚴密,我們令 arithmeticType
的值改變時,開始一個新題目:
let vm = new Vue({
///...略
watch: {
arithmeticType: function() {
this.newRound()
}
}
})
然後,把 arithmeticType
變量綁定到 html 模板中的 input
控件上:
<div id="app">
<div class="choose-type">
<input type="radio" id="addition" name="arithmetic-type" value="1" v-model="arithmeticType">
<label for="addition">addition</label>
<input type="radio" id="subtraction" name="arithmetic-type" value="2" v-model="arithmeticType">
<label for="subtraction">subtraction</label>
<input type="radio" id="multiplication" name="arithmetic-type" value="3" v-model="arithmeticType">
<label for="multiplication">multiplication</label>
<input type="radio" id="division" name="arithmetic-type" value="4" v-model="arithmeticType">
<label for="division">division</label>
</div>
<!-- 略 -->
</div>
至此,當選擇不同的運算類型時,表達式的運算符和計算結果都會自動更新爲匹配的值,比如選擇乘法時,運算符就變爲乘號,運算結果爲 2 個運算數的乘積。
不過,此時的最明顯的問題是,除法的運算數因爲是隨機生成的,商經常是無限小數,爲了更合理,我們規定這裏的除法只做整除運算。再延伸一下,對於減法,爲了避免差爲負數,也規定被減數不小於減數。
解決這個問題的辦法是在 ARITHMETIC_TYPE
枚舉中添加一個 gen()
函數,用於存儲生成運算數的邏輯,gen()
函數接收一個包含 2 個隨機數的數組作爲參數,對於加法和乘法,直接返回數組本身,減法的 gen()
函數爲 gen: ([a, b]) => a >= b ? [a, b] : [b, a]
,除法的 gen()
函數爲 gen: ([a, b]) => [a * b, b]
,經過如此處理的運算數,就可以實現上面規定的邏輯了。改造後的 ARITHMETIC_TYPE
如下:
let vm = new Vue({
///...略
data: {
///...略
ARITHMETIC_TYPE: {
ADDITION: 1,
SUBTRACTION: 2,
MULTIPLICATION: 3,
DIVISION: 4,
pproperties: {
1: {operation: '+', f: (arr) => arr, gen: ([a, b]) => [a, b]},
2: {operation: '-', f: ([x, y]) => x - y, gen: ([a, b]) => a >= b ? [a, b] : [b, a]},
3: {operation: '×', f: (arr) => arr, gen: ([a, b]) => [a, b]},
4: {operation: '÷', f: ([x, y]) => x / y, gen: ([a, b]) => [a * b, b]}
}
},
///...略
},
///...略
})
然後,在 getNumbers()
中調用 gen()
方法:
let vm = new Vue({
///...略
methods: {
///...略
getNumbers: function() {
let level = 2
let a = this.getRandomNumber(2)
let b = this.getRandomNumber(2)
// return [a, b]
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].gen([a, b])
},
///...略
},
///...略
})
至此,減法可以保證差不爲負數,除法也可以保證商是整數了。
接下來,我們來配置訓練難度。對大多數人來說,2 個二位數的加減法不是很難,但是 2 個二位數的乘除法的難度就大多了。在生成隨機數時,因爲定義了 level=2
,所以取值範圍固定是 11 ~ 99,我們希望能夠靈活配置每個運算數的取值範圍,爲此,我們需要再爲 ARITHMETIC_TYPE
枚舉中增加一個 level
屬性,用於表示隨機數的取值範圍,它是一個包含 2 個元素的數組,分別表示 2 個運算數的取值範圍,改造後的 ARITHMETIC_TYPE
如下:
let vm = new Vue({
///...略
data: {
///...略
ARITHMETIC_TYPE: {
ADDITION: 1,
SUBTRACTION: 2,
MULTIPLICATION: 3,
DIVISION: 4,
properties: {
1: {operation: '+', f: ([x, y]) => x + y, gen: (arr) => arr, level: [3, 2]},
2: {operation: '-', f: ([x, y]) => x - y, gen: ([a, b]) => a >= b ? [a, b] : [b, a], level: [3, 2]},
3: {operation: '×', f: ([x, y]) => x * y, gen: (arr) => arr, level: [2, 1]},
4: {operation: '÷', f: ([x, y]) => x / y, gen: ([a, b]) => [a * b, b], level: [2, 1]}
}
},
///...略
},
///...略
})
然後,把 getNumbers()
函數的 level
變量的值改爲從枚舉 ARITHMETIC_TYPE
中取值:
let vm = new Vue({
///...略
methods: {
getNumbers: function() {
let level = this.ARITHMETIC_TYPE.properties[this.arithmeticType].level
let a = this.getRandomNumber(level[0])
let b = this.getRandomNumber(level[1])
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].gen([a, b])
},
///...略
},
///...略
})
現在運行程序可以看到,加減法的 2 個運算數分別是 3 位數和 2 位數,而乘除法的 2 個運算數則分別是 2 位數和 1 位數,你也可以根據自己的需要來調整訓練難度。
至此,四則運算的程序邏輯全部完成,此時的 javascript 代碼如下:
let vm = new Vue({
el: '#app',
data: {
round: {all: 0, right: 0},
numbers: [0, 0],
isThinking: true,
ARITHMETIC_TYPE: {
ADDITION: 1,
SUBTRACTION: 2,
MULTIPLICATION: 3,
DIVISION: 4,
properties: {
1: {operation: '+', f: ([x, y]) => x + y, gen: (arr) => arr, level: 2},
2: {operation: '-', f: ([x, y]) => x - y, gen: ([a, b]) => a >= b ? [a, b] : [b, a], level: 2},
3: {operation: '×', f: ([x, y]) => x * y, gen: (arr) => arr, level: 1},
4: {operation: '÷', f: ([x, y]) => x / y, gen: ([a, b]) => [a * b, b], level: 1}
}
},
arithmeticType: 1,
},
computed: {
operation: function() {
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].operation
},
result: function() {
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].f(this.numbers)
},
score: function() {
return this.round.all == 1
? 100
: Math.round(this.round.right / (this.round.all - 1) * 100)
}
},
methods: {
getRandomNumber: function(level) {
let min = Math.pow(10, level - 1)
let max = Math.pow(10, level)
return min + Math.floor(Math.random() * (max - min))
},
getNumbers: function() {
let level = this.ARITHMETIC_TYPE.properties[this.arithmeticType].level
let a = this.getRandomNumber(level[0])
let b = this.getRandomNumber(level[1])
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].gen([a, b])
},
newRound: function() {
this.numbers = this.getNumbers()
this.isThinking = true
},
next: function() {
this.newRound()
this.round.all++
},
getResult: function() {
this.isThinking = false
},
answerRight: function() {
this.round.right++
this.next()
},
answerWrong: function() {
this.next()
},
},
watch: {
arithmeticType: function() {
this.newRound()
}
}
})
window.onload = vm.next
四、音效處理
引入 howler 庫:
<script src="https://cdnjs.cloudflare.com/ajax/libs/howler/2.1.1/howler.min.js"></script>
聲明變量 sound
,它有 2 個屬性 right
和 wrong
,分別代表回答正確和錯誤時的音效,屬性值是一個 Howl
對象,在構造函數中指定音頻文件的 url:
let vm = new Vue({
///...略
data: {
///...略
sound: {
right: new Howl({src: ['https://freesound.org/data/previews/203/203121_777645-lq.mp3']}),
wrong: new Howl({src: ['https://freesound.org/data/previews/415/415209_5121236-lq.mp3']})
},
},
///...略
})
在 answerRight()
方法和 answerWrong()
方法中分別調用播放聲音的 play()
方法即可:
let vm = new Vue({
///...略
methods: {
///...略
answerRight: function() {
this.round.right++
this.sound.right.play()
this.next()
},
answerWrong: function() {
this.sound.wrong.play()
this.next()
},
///...略
})
現在,當點擊綠勾時,就會響起小貓甜美的叫聲;當點擊紅叉時,響起的是小貓失望的叫聲。
至此,程序全部開發完成,最終的 javascript 代碼如下:
let vm = new Vue({
el: '#app',
data: {
round: {all: 0, right: 0},
numbers: [0, 0],
isThinking: true,
ARITHMETIC_TYPE: {
ADDITION: 1,
SUBTRACTION: 2,
MULTIPLICATION: 3,
DIVISION: 4,
properties: {
1: {operation: '+', f: ([x, y]) => x + y, gen: (arr) => arr, level: [3, 2]},
2: {operation: '-', f: ([x, y]) => x - y, gen: ([a, b]) => a >= b ? [a, b] : [b, a], level: [3, 2]},
3: {operation: '×', f: ([x, y]) => x * y, gen: (arr) => arr, level: [2, 1]},
4: {operation: '÷', f: ([x, y]) => x / y, gen: ([a, b]) => [a * b, b], level: [2, 1]}
}
},
arithmeticType: 1,
sound: {
right: new Howl({src: ['https://freesound.org/data/previews/203/203121_777645-lq.mp3']}),
wrong: new Howl({src: ['https://freesound.org/data/previews/415/415209_5121236-lq.mp3']})
},
},
computed: {
operation: function() {
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].operation
},
result: function() {
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].f(this.numbers)
},
score: function() {
return this.round.all == 1
? 100
: Math.round(this.round.right / (this.round.all - 1) * 100)
}
},
methods: {
getRandomNumber: function(level) {
let min = Math.pow(10, level - 1)
let max = Math.pow(10, level)
return min + Math.floor(Math.random() * (max - min))
},
getNumbers: function() {
let level = this.ARITHMETIC_TYPE.properties[this.arithmeticType].level
let a = this.getRandomNumber(level[0])
let b = this.getRandomNumber(level[1])
return this.ARITHMETIC_TYPE.properties[this.arithmeticType].gen([a, b])
},
newRound: function() {
this.numbers = this.getNumbers()
this.isThinking = true
},
next: function() {
this.newRound()
this.round.all++
},
getResult: function() {
this.isThinking = false
},
answerRight: function() {
this.round.right++
this.sound.right.play()
this.next()
},
answerWrong: function() {
this.sound.wrong.play()
this.next()
},
},
watch: {
arithmeticType: function() {
this.newRound()
}
}
})
window.onload = vm.next
大功告成!