标签：处理 console return one his lib har 元素 sof
ECMAScript 5 Object Array扩展
<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <title>ECMAScript5</title> <style> p{ line-height: 40px;border-bottom: 1px solid green;} </style> </head> <body> <p>1 .ES5 strict模式，变量必须有 var</p> <script> "use strict"; //testvar = 4; </script> <p>2. JSON.parse 字符串转为json</p> <script> "use strict"; var str=‘{"name":"hello"}‘; var res=JSON.parse(str); console.log("res.name: "+res.name); </script> <p>2.2 JSON.parse reviver</p> <script> "use strict"; var str2=‘{"name":"hello","age":"12"}‘; var res2=JSON.parse(str2,function(key,value){ if(typeof value == ‘string‘){ return parseInt(value); }else{ return value; } }); console.log("res2.age: " +res2.age+ ‘ ,type: ‘+typeof(res2.age)); </script> <p>3. JSON.stringfy() 过滤掉 undefined 的值 ，并格式化JSON 缩进</p> <script> "use strict"; var nums = { "first": 7, "second": 14, "third": 13 } var luckyNums = JSON.stringify(nums, function(key, value) { if (value == 13) { return undefined; // 如果 undefined 则直接被JSON忽略。 } else { return value; } }, 2); // 数字2是格式化，缩进2个空格,最大缩进10个空格。 console.log("luckyNums: "+luckyNums); </script> <p>4.1 Object.defineProperty 对象属性 ,定义 cat 对象的 name 属性 默认值为 miao 且不可以修改</p> <script> "use strict"; // 去掉 strict 不报错。 但可以显示错误 var cat={}; Object.defineProperty(cat,"name",{ value:‘miao‘, writable:false }) //cat.name=‘hehe‘; // use strict 浏览器会报错 console.log("cat.name: "+cat.name); </script> <p>4.2 Object.create()</p> <script> "use strict"; function Poker(style, title, value) { this.Style = style; this.Title = title; this.Value = value; } var pokerA = Object.create(new Poker("club", "A", 14)); console.log(Poker.constructor); //function Function() { [native code] } console.log("pokerA.Value: "+pokerA.Value); </script> <p>4.3 Object 总结：对对象的属性有了更多控制，比如是否允许被修改，删除等</p> <a href="https://msdn.microsoft.com/zh-cn/library/dn656907.aspx">Object细节</a> <p>5.1 Array 数组 isArray indexOf</p> <script> "use strict"; console.log("Array.isArray()： "+Array.isArray("xxx")); console.log("Array.isArray()： "+Array.isArray([‘a‘,‘b‘])); console.log("Array.indexOf()： "+["Hello", "javaScript", "ECMAScript", "HTML5"].indexOf("javaScript"));//1 console.log("Array.lastIndexOf()： "+["a","Hello", "javaScript"].lastIndexOf("javaScript"));//1 </script> <p>5.2 array.forEach 处理数组每一个元素</p> <script> "use strict"; var arr1 = "Charles,Mark,Bill,Vincent,William,Joseph".split(","); arr1.forEach( function(item, index) { if (index % 2 == 0) { arr1[index] = "name:" + item; } } ); arr1.forEach( function(item, index) { console.log("array.forEach()： "+item); } ); </script> <p>5.3 array.some() 一些 array.every()</p> <script> var arr11 = "Charles,Markee,Bile,Vincent,William,Joseph".split(","); console.log("array.some()： "+arr11.some( function(item, index) { return item.length < 5; } //数组是否有一些元素的长度小于5 true ) ); //true console.log("array.every()： "+arr11.every( function(item, index) { return item.length < 7; } // 所有数组元素长度都小于7 ？ false ) )//false </script> <p>5.4 array.map()</p> <script> var arr1 = "Charles,Mark,Bill,Vincent,William,Joseph".split(","); // split() 字符串转成数组 var arr2 = arr1.map( function(item, index) { if (item.indexOf("ll") > -1) { return item; } } ); arr2.forEach( function(item, index) { console.log("item: "+item); } ); </script> </body> </html>
标签：处理 console return one his lib har 元素 sof
原文地址：http://www.cnblogs.com/gyz418/p/6047866.html
