JSON stands for JavaScript Object Notation used to structure data based on JavaScript object syntax. It is small in size making it fast to transfer between server and client for transmission of information.<\/p>\n\n\n\n
JSON is based on JavaScript but due to its capability, it is implemented by many other programming languages like C, PHP, Python, etc.<\/p>\n\n\n\n
A JSON string is a string containing JSON that is needed to change in another form that can operate by JavaScript and since the objects are best suited for JavaScript, it is recommended to convert a JSON String to a JavaScript Object before performing any operations.<\/p>\n\n\n\n
There can be many ways to convert a JSON string to a JavaScript object using Node.js, but we will see the most reliable method for this which is the JSON.parse() method.<\/p>\n\n\n\n
Also Read:<\/em><\/strong> NodeJS Convert String To Int \u2013 A Step-by-Step Guide<\/em><\/strong><\/a><\/p>\n\n\n\n The structure of JSON is simpler and easy to read by humans. Below is a JSON string containing two keys, name and age, along with their value.\u00a0<\/p>\n\n\n Here we are using backticks (template literals) in place of quotation marks which are commonly used for string representation. We use backticks to avoid invalid JSON string errors that can occur when we define a string using single quotes or double quotes and do not escape the corresponding quotes inside that string properly. Additionally, the template allows multiline strings without literal line breaks.<\/p>\n\n\n\n Below is a JavaScript object with the same key-value pairs as above.<\/p>\n\n\n In JSON string the keys and value are wrapped inside double quotes (“), whereas in JavaScript object it is not required to wrap the key and value inside double quotes instead you can write the key without having any type of quotation marks and wrap the value if it is a string inside single or double quotes.<\/p>\n\n\n\n There is an exception that if the key contains special characters such as dashes (-), it must be wrapped inside single quotes (‘) to make it a valid JavaScript object.<\/p>\n\n\n There is a method JSON.parse()<\/strong> that can convert a JSON string to an object literals in JavaScript. This method takes a JSON string as an argument, converts the string into an object, and returns it.<\/p>\n\n\n\n Parameters:<\/strong><\/p>\n\n\n\n Example:<\/strong><\/p>\n\n\n\n We have a JSON string containing multiple values and arrays.<\/p>\n\n\n Pass this as an argument to JSON.parse() <\/strong>method to convert it into a JavaScript Object.<\/p>\n\n\n Print the returned Object in the console.<\/p>\n\n\n Output:<\/strong><\/p>\n\n\n Here you can see that the return value is an object meaning we have successfully converted JSON string into a JavaScript object.<\/p>\n\n\n\n It may be possible that the string you are trying to convert is not a valid JSON string and hence it may cause unexpected behaviour of the code making error handling necessary, let’s see how.<\/p>\n\n\n\n Example:<\/strong><\/p>\n\n\n Here the given string is not a valid JSON string so the code inside the catch block will be executed. You can take more control over the program by writing your own code in catch block.<\/p>\n\n\n\n Output:<\/strong><\/p>\n\n\n In case you want, you can convert the JavaScript object back to a JSON-formatted string using another special method, JSON.stringify().<\/p>\n\n\n\n Example:<\/strong><\/p>\n\n\n Output:<\/strong><\/p>\n\n\n We got the same result from where we started.<\/p>\n\n\n\nStructure of JSON String<\/h2>\n\n\n\n
\nconst JSONString = `{\n "fullname": "Stardew Valley", \n "age": 30\n}`;\n<\/pre><\/div>\n\n\nStructure of JavaScript Object\u00a0<\/h2>\n\n\n\n
\nconst javascriptObject = {\n fullName: 'Stardew Valley',\n age: 30\n}\n<\/pre><\/div>\n\n\nDifference Between JSON String and JavaScript Object<\/h2>\n\n\n\n
\nconst javascriptObject = {\n fullName: 'Stardew Valley',\n age: 30,\n 'is-vegetarian': true,\n}\n<\/pre><\/div>\n\n\nConvert JSON String to JavaScript Object Using JSON.parse()<\/h2>\n\n\n\n
Syntax of JSON.parse()<\/h3>\n\n\n
\nJSON.parse(JSONString[, optionalFunction]);\n<\/pre><\/div>\n\n\n
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\nconst JSONString = `{\n "fullname": "Stardew Valley", \n "age": 30, \n "is-vegetarian": true,\n "hobbies": ["farming", "fishing", "mining", "foraging", "fighting"],\n "address": {"street": "123 Main St", "city": "Pelican Town", "state": "California", "zip": "12345"},\n "phone-numbers": [{"type": "home", "number": "123-456-7890"}, {"type": "work", "number": "123-456-7890"}] \n}`;\n<\/pre><\/div>\n\n\n\nconst javascriptObject = JSON.parse(JSONString);\n<\/pre><\/div>\n\n\n
\nconsole.log(javascriptObject);\n<\/pre><\/div>\n\n\n
Complete Code to Convert JSON to JavaScript Object<\/h3>\n\n\n
\nconst JSONString = `{\n "fullname": "Stardew Valley", \n "age": 30, \n "is-vegetarian": true,\n "hobbies": ["farming", "fishing", "mining", "foraging", "fighting"],\n "address": {"street": "123 Main St", "city": "Pelican Town", "state": "California", "zip": "12345"},\n "phone-numbers": [{"type": "home", "number": "123-456-7890"}, {"type": "work", "number": "123-456-7890"}] \n}`;\n\nconst javascriptObject = JSON.parse(JSONString);\n\nconsole.log(javascriptObject);\n<\/pre><\/div>\n\n\n\n{\n fullname: 'Stardew Valley',\n age: 30,\n 'is-vegetarian': true,\n hobbies: [ 'farming', 'fishing', 'mining', 'foraging', 'fighting' ],\n address: {\n street: '123 Main St',\n city: 'Pelican Town',\n state: 'California',\n zip: '12345'\n },\n 'phone-numbers': [\n { type: 'home', number: '123-456-7890' },\n { type: 'work', number: '123-456-7890' }\n ]\n}\n<\/pre><\/div>\n\n\nHandling Error\u00a0<\/h3>\n\n\n\n
\nconst JSONString = 'Hello World!';\n\ntry {\n const javascriptObject = JSON.parse(JSONString);\n console.log(javascriptObject); \n} catch (error) {\n console.log("Please insert a valid JSON string");\n}\n<\/pre><\/div>\n\n\n\nPlease insert a valid JSON string\n<\/pre><\/div>\n\n\n
Convert JavaScript Object To JSON String Using JSON.stringify()<\/h2>\n\n\n\n
\nconst javascriptObject = {\n fullname: 'Stardew Valley',\n age: 30,\n 'is-vegetarian': true,\n hobbies: ['farming', 'fishing', 'mining', 'foraging', 'fighting'],\n address: {\n street: '123 Main St',\n city: 'Pelican Town',\n state: 'California',\n zip: '12345'\n },\n 'phone-numbers': [\n { type: 'home', number: '123-456-7890' },\n { type: 'work', number: '123-456-7890' }\n ]\n};\n\nconst JSONString = JSON.stringify(javascriptObject);\nconsole.log(JSONString);\n<\/pre><\/div>\n\n\n\n{\n "fullname": "Stardew Valley",\n "age": 30,\n "is-vegetarian": true,\n "hobbies": ["farming", "fishing", "mining", "foraging", "fighting"],\n "address": {\n "street": "123 Main St",\n "city": "Pelican Town",\n "state": "California",\n "zip": "12345"\n },\n "phone-numbers": [\n {"type": "home", "number": "123-456-7890"},\n {"type": "work", "number": "123-456-7890"}\n ]\n}\n<\/pre><\/div>\n\n\n