JavaScript 使用循環語句查找通訊錄
1
我們有一個聯繫人列表,裏面存儲着不同聯繫人的數組對象。
函數 lookUpProfile
有兩個預定義參數:firstName
值和prop
屬性 。
該函數應檢查firstName是實際聯繫人的firstName,給定的屬性(prop)是該聯繫人的屬性。
如果它們都存在,函數返回prop
屬性對應的值。
如果firstName
值不存在,返回 "No such contact"
。
如果prop
屬性不存在,返回 "No such property"
。
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUpProfile(firstName, prop){
// Only change code below this line
for( var i = 0; i < contacts.length; i++){
if(firstName == contacts[i]["firstName"]){
if(contacts[i][prop]){
return contacts[i][prop];
}
else{
return "No such property";
}
}
return "No such contact";//循環執行結束後返回這一句
}
應該爲if(i == contacts.length-1 ){
return "No such contact";
// Only change code above this line
}
// Change these values to test your function
lookUpProfile("Akira", "likes");
2
function randomRange(myMin, myMax) {
return Math.floor(Math.random() * (myMax - myMin + 1)) + myMin; // Change this line
將一個 零到一之間的隨機數 * (myMax - myMin + 1) 後向下取整+myMin
作用是保證myMax和myMin之間的每個數都能取到,記錄重點在+1,保證能取到myMax
}