[javascript] How to test if a string is JSON or not?

This code is JSON.parse(1234) or JSON.parse(0) or JSON.parse(false) or JSON.parse(null) all will return true.

function isJson(str) {
    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}

So I rewrote code in this way:

function isJson(item) {
    item = typeof item !== "string"
        ? JSON.stringify(item)
        : item;

    try {
        item = JSON.parse(item);
    } catch (e) {
        return false;
    }

    if (typeof item === "object" && item !== null) {
        return true;
    }

    return false;
}

Testing result:

isJson test result

Examples related to javascript

need to add a class to an element How to make a variable accessible outside a function? Hide Signs that Meteor.js was Used How to create a showdown.js markdown extension Please help me convert this script to a simple image slider Highlight Anchor Links when user manually scrolls? Summing radio input values How to execute an action before close metro app WinJS javascript, for loop defines a dynamic variable name Getting all files in directory with ajax

Examples related to mysql

Implement specialization in ER diagram How to post query parameters with Axios? PHP with MySQL 8.0+ error: The server requested authentication method unknown to the client Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver' phpMyAdmin - Error > Incorrect format parameter? Authentication plugin 'caching_sha2_password' is not supported How to resolve Unable to load authentication plugin 'caching_sha2_password' issue Connection Java-MySql : Public Key Retrieval is not allowed How to grant all privileges to root user in MySQL 8.0 MySQL 8.0 - Client does not support authentication protocol requested by server; consider upgrading MySQL client

Examples related to json

Use NSInteger as array index Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>) HTTP POST with Json on Body - Flutter/Dart Importing json file in TypeScript json.decoder.JSONDecodeError: Extra data: line 2 column 1 (char 190) Angular 5 Service to read local .json file How to import JSON File into a TypeScript file? Use Async/Await with Axios in React.js Uncaught SyntaxError: Unexpected token u in JSON at position 0 how to remove json object key and value.?