How to convert a json string to a json object in js-javascript tips-js tutorial

Converts a json string to a json object. During data transmission, json is transmitted in the form of text, that is, strings, while JS operates on JSON objects. Therefore, mutual conversion between JSON objects and JSON strings is critical. For example:

JSON string:
Var str1 = '{"name": "cxh", "sex": "man "}';
JSON object:
Var str2 = {"name": "cxh", "sex": "man "};

1. convert a JSON string to a JSON object

To use str1 above, you must use the following method to first convert it to a JSON object:

// Converts a JSON string to a JSON object

Var obj = eval ('+ str + ')');

Or

Var obj = str. parseJSON (); // converts a JSON string to a JSON object.

Or

Var obj = JSON. parse (str); // converts a JSON string to a JSON object.

Then, you can read:

Alert (obj. name );

Alert (obj. sex );

NOTE: If obj is a JSON object, it is still a JSON object after eval () function conversion (even Multiple conversions), but parseJSON () is used () A problem occurs after the function is processed (a syntax exception is thrown ).

2. You can use toJSONString () or the global method JSON. stringify () to convert a JSON object to a JSON string.

For example:

Var last = obj. toJSONString (); // converts a JSON object to a JSON character

Or

Var last = JSON. stringify (obj); // converts a JSON object to a JSON character

Alert (last );

Note:

Among the methods above, except that the eval () function is provided by js, several other methods are from the json. js package. The new JSON version modifies the API and changes JSON. stringify () and JSON. both parse () methods are injected into the built-in Javascript Object, and the former becomes the Object. toJSONString (), and the latter is a String. parseJSON (). If you cannot find the toJSONString () and parseJSON () methods, the version of your json package is too low.