I have never understood json very well. I recently read some introductions and found out that this thing is so easy to use. Let me introduce it to you below
1. We can add/delete parameters to a function at any time or add new ones at any parameter position. Parameters do not have to be written in a prescribed order like traditional parameters, and each time a parameter of the function is added or deleted, the function content must be modified. When using JSON as a parameter, you don't need to consider the order of parameters.
Look at the code demonstration below:
<script type="text/javascript"> <!-- //普通方法 function commonArg(name,age,desc){ var userinfo="name: "+name+","+"age: "+age+"\ndescription: "+desc; alert(userinfo); } commonArg("yemoo",22,"a boy!")//每次调用都必须按照规定的参数顺序书写,如果写成commonArg(22,"yemoo","desc")则返回信息就不对,每次都必须记忆每个参数意义及顺序 //JSON参数法 function jsonArg(info){ var userinfo="name: "+info.name+"\tage: "+info.age+"\ndescription: "+info.desc; alert(userinfo); } jsonArg({name:"blue",age:22,desc:"a gril?"}); jsonArg({desc:"not a people!",name:"sss",age:0}); //参数位置可以随意写 //--> </script>
The shortcomings of ordinary functions are obvious: the meaning and order of parameters must be remembered. This is not required when using JSON.
2. It is very convenient for users to call functions, especially when only a few or one of the parameters need to be passed in.
Look at the code demonstration below:
<script type="text/javascript"> <!-- //普通方法 function commonArg(name,age,desc){ var userinfo="name: "+(name||"empty")+"\tage: "+(age||0)+"\ndescription: "+desc||"empty"; alert(userinfo); } //当只需要设定后面的参数时前面每个参数都需要设置为null commonArg("tempUser"); commonArg(null,null,"a boy!"); commonArg(null,20); //JSON参数法 function jsonArg(info){ var userinfo="name: "+(info.name||"empty")+"\tage: "+(info.age||0)+"\ndescription: "+(info.desc||"empty"); alert(userinfo); } //每次只需要设置需要设定参数项 jsonArg({name:"tempUser"}); jsonArg({desc:"a boy!"}); jsonArg({age:20}); //--> </script>
The advantages of the JSON method are obvious: you only need to pass in the required parameters each time, without considering other parameters.
JSON is really a useful thing. It does not need to be used in ajax or other aspects of js. It reflects its convenient and flexible characteristics. You should really explore and learn json.