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Syntax Foundations
JSON object JSON array String value Number value Boolean value Null value Nested objects Nested arrays
String Rules
Escaped quote Backslash escape Newline escape Unicode escape Surrogate pair Control character restriction Property names require quotes Whitespace rules
Numbers & Types
Integer number Decimal number Exponent notation Negative number No NaN No Infinity No comments No trailing commas
Data Modeling
Object versus array Array of objects Lookup object Optional property with null Nested resource Flat resource Identifier field Versioned payload
JavaScript Integration
JSON.parse JSON.stringify Pretty printing Replacer function Reviver function Omit undefined Date serialization BigInt serialization strategy
API Payloads
Request body Response envelope Error object Pagination metadata Cursor pagination Problem details shape Patch-like payload Webhook event payload
Validation
Required property concept Type constraint concept Enum constraint concept Array item constraint String length constraint Numeric range constraint Pattern constraint Additional properties concept
Operations
Canonical key ordering Minification Pretty formatting NDJSON records JSON Lines streaming Deep clone caveat Prototype safety Large document parsing strategy
JSON / Operations

Prototype safety

Learn Prototype safety in JSON with a dedicated explanation, a topic-specific example, edge guidance, and a mastery check.

12 min read • Advanced
json-063.json
json 
const input=JSON.parse('{"__proto__":{"admin":true},"name":"guest"}');
const safe=Object.create(null);
for(const [k,v] of Object.entries(input)) if(k!=="__proto__") safe[k]=v;
console.log(safe.name);
What to watch
Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

Prototype safety Mastery Check →
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Large document parsing strategy