1. 定义：用于在数组的末端添加一个或多个元素，并返回添加新元素后的数组长度。注意，该方法会改变原数组 2. 代码使用push方法，往数组中添加了四个成员1 var arr = []; 2 console.log(arr.push(1)); //1 3 console.log(arr.push(a)); //2 4 console.log(arr.push(true,{}));//4 5 console.log(arr); // [1, a, true, {}]?
构造函数里用this和.prototype.的区别<span style="font-size:18px;">function Foo() {this.a = function() {alert('hahaha')}; } </span>var bar = new Foo();bar.a();和<span style="font-size:18px;">function Foo() { } Foo.prototype.a = function() {alert('hahaha') }; var bar = new Foo(); bar.a();</span> function Foo() {}Foo.prototype.a = function() { alert(‘hahaha‘)};var bar = new Foo();bar.a();在结果上看是...
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>Title</title><style>.g{background-color: #cccccc;color: #000;text-align: center;font-size: 60px;}</style></head><body><div class=‘g‘ id="1">来呀~造作呀</div><script>setInterval( function (){d=document.getElementById(‘1‘);d_text=d.innerText;sub_char=d_text.slice(1,d_text.length);first_char=d_text[0];new_str=sub_char+first_char;d....