In this section, we mainly discuss JSON parsing.
The JSON. parse () method can also receive another parameter, which is a function that calls each key-Value Pair early. To distinguish JSON. the replacer function received by stringify (). This function is called the restore function (reviver ), but in fact, the signatures of these two functions are the same-they both receive connection parameters, one key and one value, and both need to return a value.
If the restore function returns undefined, the corresponding key is to be deleted from the result. If other values are returned, the value is inserted into the result. For example:CopyCodeThe Code is as follows: <HTML>
<Head>
<Title> </title>
<SCRIPT type = "text/JavaScript">
Function Init ()
{
VaR student = {
Name: "bill ",
Birthdate: new date (1990,8, 4)
};
VaR jsontext = JSON. stringify (student );
VaR studentobject = JSON. parse (jsontext, function (Key, value ){
If (Key = "birthdate ")
{
Return new date (value );
}
Else
{
Return value;
}
});
}
</SCRIPT>
</Head>
<Body>
<Input type = "button" onclick = "Init ()" value = "test"/>
</Body>
</Html>
The code above first adds the birth date birthdate attribute for student, which stores a date object. This object becomes a valid JSON string after serialization, and is parsed and restored to a date object in studentobject.