JSON

最新推荐文章于 2025-08-09 16:13:36 发布

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最新推荐文章于 2025-08-09 16:13:36 发布

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文章标签： json javascript python ViewUI

原文链接：https://my.oschina.net/langgege/blog/1083548

2019独角兽企业重金招聘Python工程师标准>>>

stringify()和parse():分别是将JavaScript对象序列化为JSON字符串和把JSON字符串解析为原生的JavaScript值.

1.stringify():

        var book = {
                        title: "Professional JavaScript",
                        authors: [
                            "Nicholas C. Zakas"
                        ],
                        edition: 3,
                        year: 2011
                   };
        
        var jsonText = JSON.stringify(book);
        alert(jsonText);
        //{"title":"Professional JavaScript","authors":["Nicholas C.Zakas"],"edition":3,"year":2011}

        var bookCopy = JSON.parse(jsonText);

stringify()还接受一个数组作为第二个参数,数组的值对应将要序列化的对象属性

        var book = {
                        title: "Professional JavaScript",
                        authors: [
                            "Nicholas C. Zakas"
                        ],
                        edition: 3,
                        year: 2011
                   };

        var jsonText = JSON.stringify(book, ["title", "edition"]);
        alert(jsonText);
        //{"title":"Professional JavaScript","edition":3}

stringify()还接受一个函数作为第二个参数:

        var book = {
                        title: "Professional JavaScript",
                        authors: [
                            "Nicholas C. Zakas"
                        ],
                        edition: 3,
                        year: 2011
                   };

        var jsonText = JSON.stringify(book, function(key, value){
            switch(key){
                case "authors":
                    return value.join(",")
                 
                case "year":
                    return 5000;
                    
                case "edition":
                    return undefined;//如果返回了undefined.那么相应的属性会被忽略
                    
                default:
                    return value;
            }
        });
        alert(jsonText);
        //{"title":"Professional JavaScript","authors":"Nicholas C. Zakas","year":5000}

2.toJSON():如果JSON.stringify()不能满足对某些对象进行自定义序列化的需求,可以给对象定义toJSON()方法.

        var book = {
                       "title": "Professional JavaScript",
                        "authors": [
                            "Nicholas C. Zakas"
                        ],
                        edition: 3,
                        year: 2011,
                        toJSON: function(){
                            return this.title;
                        }
                   };

        var jsonText = JSON.stringify(book);
        alert(jsonText);//"Professional JavaScript"

3.parse()也可以接受一个函数作为第二个参数

        var book = {
                       "title": "Professional JavaScript",
                        "authors": [
                            "Nicholas C. Zakas"
                        ],
                        edition: 3,
                        year: 2011,
                        releaseDate: new Date(2011, 11, 1)
                   };

        var jsonText = JSON.stringify(book);
        console.log(jsonText);
        //{"title":"Professional JavaScript","authors":["NicholasC.Zakas"],"edition":3,"year":2011,"releaseDate":"2011-11-30T16:00:00.000Z"}
        
        var bookCopy = JSON.parse(jsonText, function(key, value){
            if (key == "releaseDate"){
                return undefined;
            } else {
                return value;
            }
        });
		
        console.log("releaseDate" in bookCopy);//false
        console.log(bookCopy);//
/*Array(1)
0:"Nicholas C. Zakas"
length:1
__proto__:
Array(0)
edition:3
title:"Professional JavaScript"
year:2011*/

转载于:https://my.oschina.net/langgege/blog/1083548