JavaScript

JSON (JavaScript Object Notation) syntax is a set of rules that define how data is structured in JSON format. It is a lightweight, text-based format that is used to store and transfer data, especially between a client and a server.

The syntax is derived from JavaScript object literals, but JSON is a string format that is language-independent.

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📜 JSON Syntax Rules

1. Data is written as key/value pairs.
2. Keys must be strings, written inside double quotes.
3. Values can be:
   • String
   • Number
   • Boolean
   • Null
   • Object (another JSON object)
   • Array
4. Objects are wrapped in { }.
5. Arrays are wrapped in [ ].
6. Commas separate pairs or elements.
7. JSON does not support comments.

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✅ JSON Syntax Example

{
  "name": "John",
  "age": 28,
  "isEmployed": true,
  "skills": ["HTML", "CSS", "JavaScript"],
  "address": {
    "city": "Mumbai",
    "zip": "400001"
  },
  "spouse": null
}

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🔍 Explanation of Syntax

Element	Type	Description
"name"	String	Must be in double quotes
28	Number	No quotes required
true	Boolean	Must be lowercase (true or false)
["HTML",...]	Array	List of values in square brackets
{...}	Object	Nested object inside the main object
null	Null	Represents an empty value

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❌ Invalid JSON Examples

Here are some examples that will result in errors:

1. ❌ Single Quotes

{ 'name': 'John' }

✅ Use double quotes: { "name": "John" }

2. ❌ Trailing Commas

{
  "name": "John",
  "age": 28,
}

✅ Remove the last comma.

3. ❌ Comments

{
  "name": "John" // This is not allowed
}

✅ JSON does not support comments. Remove them.

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🧠 Summary

• JSON syntax is strict and simple.
• It is based on key/value pairs.
• Use double quotes for all keys and string values.
• Values must be valid types: string, number, object, array, boolean, or null.
• Do not include functions or comments in JSON.

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