面試題彙總:
今日頭條:
已知如下類Animal,要求設計一個Cat類繼承自Animal,並實現如下功能:
Animal:function Animal(){
this.name = "Animal";
this.showName = function(){
console.log(this.name);
}
}
Cat:function Cat(){
this.name = "Cat";
this.showName1 = function(){
console.log(this.name);
}
this.showName2 = function(){
console.log(this.name);
}
this.showName3 = function(){
console.log(this.__super.name + "=>" + this.name);
}
}
代碼運行:
// 請完善Cat部分相關代碼,得到如下結果:
var cat = new Cat();
console.log(cat instanceof Animal ); // 得到:true
cat.showName1(); // 得到:"Cat" (需要讀到Cat中的name屬性)
cat.showName2(); // 得到:”Animal" (需要讀到Animal中的name屬性)
cat.showName3(); //得到:”Animal" => "Cat" (需要同時讀到Cat中的name和Animal中的name)
解析:
function Animal() {
this.name = "Animal";
this.showName = function() {
console.log(this.name);
};
}
function Cat() {
this.name = "Cat";
this._super = Cat.prototype;
this.showName1 = function() {
console.log(this.name);
};
this.showName2 = function() {
console.log(this.name);
};
this.showName3 = function() {
console.log(this._super.name + "=>" + this.name);
};
}
Cat.prototype = new Animal();
var cat = new Cat();
console.log(cat instanceof Animal); //true
cat.showName1(); //"Cat"
cat.showName2.call(Cat.prototype); //"Animal"
cat.showName3(); //"Animal" => "Cat"
第二題:
已知道如下數組:
var arr = [[1,2,2],[3, 4, 5, 5],[6, 7, 8, 9,[11,12,[12,13,[14]]]],10];
編寫一個程序將數組扁平化去併除其中重複部分數據,最終得到一個升序且不重複的數組:
var res= [1,2,3,4,5,6,7,8,9,10,11,12,13,14]
解析:
/**
* 解析數組,然後去重,排序
* @type Array
*/
<strong>//解析數組</strong>
var arr = [[1, 2, 2], [3, 4, 5, 5], [6, 7, 8, 9, [11, 12, [12, 13, [14]]]], 10];
var newArray = [];
function getArray(array) {
array.forEach(function(e) {
if (typeof e === "object") {
getArray(e);
} else {
newArray.push(e);
}
});
}
getArray(arr);
<strong>//去重</strong>
Array.prototype.distinct = function() {
return this.reduce(function(newArray1, newValue) {
if (newArray1.indexOf(newValue) === -1)
newArray1.push(newValue);
return newArray1;
}, []);
};
newArray = newArray.distinct();
<strong>//排序</strong>
newArray.sort(function(a, b) {
return a - b;
});
console.log(newArray);
第三題:
如下題目存在哪些問題(改錯)?
var obj = {
name: " jsCoder",
skill: ["css3","html5", "es6", "react", "angular"],
say: function () {
for(var i = 0, len = this.skill.length; i< len; i++){
setTimeout(function(){
console.log("No." + i + this.name);
console.log(this.skill[i]);
console.log('--------------------------');
},100);
}
}
}
obj.say();
如何得到結果,能想到幾種方法:
<span style="font-size:18px;">No.1 jsCoder
css3
--------------------------
No.2 jsCoder
html5
--------------------------
No.3 jsCoder
es6
--------------------------
No.4 jsCoder
react
--------------------------
No.5 jsCoder
angular
-------------------------- </span>
解析:
<span style="font-size:18px;">/**
* 考察this指向、閉包
*
*/
var obj = {
name: " jsCoder",
skill: ["css3", "html5", "es6", "react", "angular"],
say: function() {
for (var i = 0, len = this.skill.length; i < len; i++) {
(function() {
var temp = i;
setTimeout(function() {
console.log("No." + temp + obj.name);
console.log(obj.skill[temp]);
console.log('--------------------------');
}, 100);
})();
}
}
};
obj.say();</span>