Generating and parsing Json__json in JS

Generate JSON object in JS

Parse JSON string in JS:

1.eval ("..."):

var a_id=eval (' {' Name ': 123} ');

If the contents of the eval contain malicious script, it's a hassle.

2.json_parse:

Need to import Json_parse.js:

<script src= "Js/json_parse.js" ></script>
<script language= "JavaScript" >
var t = json_parse (' {' Name ': 123} ');
alert (t.name);
</script>>

Security, fast resolution

3.var Vjson = Json.parse (JSONSTR):

Supports both IE8 and FIREFOX3 browsers with built-in JSON objects, and other browsers to introduce json.js files

<script src= "Js/json.js" ></script>
<script language= "JavaScript" >
var t = json.parse (' {' Name ': 123} ');
alert (t.name);
</script>
Security, parsing speed is also very fast.

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Parse JSON string in JS

Json.stringify:

Syntax:
Json.stringify(value [, Replacer] [, space])
Value: Is the field that must be required. Are the objects you enter, such as arrays, classes, and so on.
Replacer: This is optional. It is divided into 2 ways, one is the method, the second is the array.
Case one: Let's start with the data, and we can see from the experiments that we have later that it is related to the first one. In general, our serialized results are represented by key-value pairs.
For example:
Name: "LAN", age:25
This form.
So, if this form is the case, if the second value is present in the first, then the second value is the key, the first value is represented by value, and if not, sorry, ignored. "is not a little abstract, I think so, but you wait and see the experiment OK." Whirring 】
Situation Two: If it is a method, it is very simple, that is, the serialization of each object (remember each) into the method of processing.
Space: Well understood, with what to do the separator.
1. If omitted, the displayed value does not have a separator character. Direct output to
2. If it is a number, then it is defined to indent a few characters, of course, if greater than 10, the maximum value is 10.
3. If there are some escape characters, such as "\ T", which indicates carriage return, then it is a carriage return per line.
4. If it's just a string, OK, just append the string to each line when you output the value. Of course, the maximum length is 10 characters.
start with an example to illustrate;
1. In the case of only one parameter:
Copy code code as follows:
var student = new Object ();
Student.name = "Lanny";
Student.age = "25";
Student.location = "the";
var json = json.stringify (student);
alert (student);

The results are as follows:

Some people may doubt the role of Json.stringify, OK. Well, if we don't want this function. Following the code:
Copy code code as follows:
var student = new Object ();
Student.name = "Lanny";
Student.age = "25";
Student.location = "the";

var json = json.stringify (student);
alert (student);

Congratulations on your results:

Don't lie to you, go on.
2. The second parameter exists and the second parameter is a function
Copy code code as follows:
var students = new Array ();
Students[0] = "Lanny";
Students[1] = "dong";
STUDENTS[2] = "I love You";
var json = json.stringify (students,switchupper);
function Switchupper (key, value) {
Return value.tostring (). toUpperCase ();
}
alert (JSON);

var json = json.stringify (students, function (Key,value) {

Return value.tostring (). toUpperCase ();

//});

The above method can also be replaced by the following, 2 are the same, but the wording is a little bit different.
The results were as follows:

3. The second parameter exists, and the second argument is not a function, but an array.
3.1 "Misunderstanding" if the first argument is an array, and the second argument is an array, only the value of the first argument is displayed.
Like what:
Copy code code as follows:
var students = new Array ();
Students[0] = "Lanny";
Students[1] = "dong";
STUDENTS[2] = "I love You";
var stu = new Array ();
Stu[0] = "1";
STU[1] = "2";
var json = json.stringify (STUDENTS,STU);
alert (JSON);

The result of Sorry is:

The second one was ignored, but the first one was serialized.

3.2 If the first is an object (the object here is like a new one in C #), the second is an array.

So if the value of the second one exists in the first, then the second value is the key, and the first value represents
Copy code code as follows:
var student = new Object ();
STUDENT.QQ = "5485891512";
Student.name = "Lanny";
Student.age = 25;

var stu = new Array ();
Stu[0] = "QQ";
STU[1] = "age";
STU[2] = "Hi";//This student object does not exist.

var json = json.stringify (STUDENT,STU);
alert (JSON);

The results obtained are as follows:

Because stu[2] = "HI"; this hi is not found in the first one, so it is not displayed.

4. Third parameter

4.1. If omitted, the displayed value does not have a separator character. Direct output to

Like what:
Copy code code as follows:
var student = new Object ();
STUDENT.QQ = "5485891512";
Student.name = "Lanny";
Student.age = 25;

var stu = new Array ();
Stu[0] = "QQ";
STU[1] = "age";
STU[2] = "Hi";

var json = json.stringify (STUDENT,STU);
alert (JSON);

The output is:

4.2. If it is a number, then it is defined to indent a few characters, of course, if greater than 10, the maximum value is 10.
Copy code code as follows:
var student = new Object ();
STUDENT.QQ = "5485891512";
Student.name = "Lanny";
Student.age = 25;

var stu = new Array ();
Stu[0] = "QQ";
STU[1] = "age";
STU[2] = "Hi";

var json = json.stringify (student,stu,100);/note here's 100.
alert (JSON);

So what you get is:

10 characters were empty.

4.3. If there are some escape characters, such as "\ T", which indicates carriage return, then it is a carriage return per line.

is the same.

4.4. If it's just a string, OK, just append the string to each line when you output the value. Of course, the maximum length is 10 characters.

If it is var json = json.stringify (Student,stu, "Haikou");