ステップアップタスク11
3601 ワード
テーマ1:次のコード出力はいくらですか?コードを修正してfnArriにiを出力させます.2つ以上の方法を使う
for (var i = 0; i < 10; i ++) {
fnArr[i] = function(){
return i;
};
}
``` console.log( fnArr[3]() ); // 10, i 10, 10
:
``` var fnArr = [];
for (var i = 0; i < 10; i ++) {
(function(i){
fnArr[i] = function(){
return i;
}
})(i);
}
``` console.log( fnArr[3]() ); //3
:
``` var fnArr = [];
for (var i = 0; i < 10; i ++) {
fnArr[i] = (function(i){ //IIFE &
return function(){
return i;
}
})(i);
}
``` console.log( fnArr[3]() ); //3
:
``` var fnArr = [];
for (let i = 0; i < 10; i ++) { // ES6: let
fnArr[i] = function(){
return i;
};
}
``` console.log( fnArr[3]() );
2: ,
```var Car = (function () {
let speed = 0;
function setSpeed(s){
return speed = s;
}
function getSpeed(){
return speed;
}
function accelerate(){
return speed+=10;
}
function decelerate(){ //
return speed>0?speed-=10:speed;
}
function getStatus(){
return speed>0?'running':'stop';
}
return {
"setSpeed" : setSpeed,
"getSpeed" : getSpeed,
"accelerate" : accelerate,
"decelerate" : decelerate,
"getStatus" : getStatus
}
})();
Car.setSpeed(30);
Car.getSpeed(); //30
Car.accelerate();
Car.getSpeed(); //40;
Car.decelerate();
Car.decelerate();
Car.getSpeed(); //20
Car.getStatus(); // 'running';
Car.decelerate();
Car.decelerate();
Car.getStatus(); //'stop';
```//Car.speed; //error
3: ? ?
```var a = 1;
setTimeout(function(){
a = 2;
console.log(a);//2
}, 0); // 0,
var a ;
console.log(a); //1
a = 3;
```console.log(a); //3
4: ? ?
```var flag = true;
setTimeout(function(){//
flag = false;
},0)
while(flag){} //setTimeout , flag true, 。
```console.log(flag); //
5: ? delayer: 0, delayer:1...( )
```for(var i=0;i<5;i++){
(function(t){
// let t;
return setTimeout(function(){
console.log('delayer:' + t );
}, 0);
})(i);
console.log(i);
```}
6: ?
```function trueStyle(element,pseduoElement){
//IE window.getComputedStyle(), element.currentStyle();
return element.currentStyle ? element.currentStyle : window.getComputedStyle(element,pseduoElement);
}
let trueWidth = trueStyle(element).width;
```let trueHeight = trueStyle(element).height;
7:URL ? ?
```let myURL = 'https://www.google.com/#q=javascript';
// URL ( ), encodeURI();
let simpleURL = encodeURI(myURL); //"https://www.google.com/#q=javascript"
// URL URL , encodeURIComponent();
let completeURL = encodeURIComponent(myURL);
let newURL = 'https://www.google.com/?back=' + completeURL; //"https://www.google.com/?back=https%3A%2F%2Fwww.google.com%2F%23q%3Djavascript"
window.open(simpleURL); // , ```https://www.google.com/#q=javascript
8: ,
```function isAndroid(){
return /Android/.test(navigator.userAgent);
}
funcnction isIphone(){
return /iPhone/.test(navigator.userAgent);
}
function isIpad(){
return /iPad/.test(navigator.userAgent);
}
function isIOS(){
return /(iPad)|(iPhone)/i.test(navigator.userAgent);
```}