Json.parse () and Eval ()

First, preface

as with XML, JSON is also a data format based on plain text. Since JSON is inherently prepared for JavaScript, the JSON data format is very simple, you can transfer a simple string,number,boolean with JSON, or you can transfer an array, or a complex object.

Second, a string containing a JSON object

basic formula: var jsondata= ' { "data1": "Hello,", "data2": " world! "

Three, the analytic method of JSON

(1) use Json.parse ()

<script>
var str = ' {' name ': ' Party ', ' age ': ' 23 '} ';
var ob=json.parse (str);
alert (ob.name);
alert (ob.age);

var str = ' [' Name ', ' age '] ';
var ob=json.parse (str);
Alert (ob[0]);
Alert (ob[1]);
</script>

(2) Use eval ()

var str = ' {' name ': ' Party ', ' age ': ' 23 '} ';
var ob=eval("("+str+")");

alert (ob.name);
alert (ob.age);

Note: Json.parse () can parse data in JSON format, and will format the string to be parsed, not parse if it is malformed, and eval () can parse any string, especially third-party JSON data (which may contain malicious code). Using eval is dangerous and prone to memory leaks, so use the Json.parse () method to parse strings in your code whenever possible.

Json.parse () and Eval ()