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node.js is there any proper way to parse JSON with large numbers? (long, bigint, int64)

Posted by: admin November 29, 2017 Leave a comment

Questions:

When I parse this little piece of JSON

{ "value" : 9223372036854775807 }

that’s what I get

{ hello: 9223372036854776000 } 

Is there any way to parse it properly?

Answers:

Not with built-in JSON.parse. You’ll need to parse it manually and treat values as string (if you want to do arithmetics with them there is bignumber.js) You can use Douglas Crockford JSON.js library as a base for your parser.

EDIT: I created a package for you 🙂

var JSONbig = require('json-bigint');

var json = '{ "value" : 9223372036854775807, "v2": 123 }';
console.log('Input:', json);
console.log('');

console.log('node.js bult-in JSON:')
var r = JSON.parse(json);
console.log('JSON.parse(input).value : ', r.value.toString());
console.log('JSON.stringify(JSON.parse(input)):', JSON.stringify(r));

console.log('\n\nbig number JSON:');
var r1 = JSONbig.parse(json);
console.log('JSON.parse(input).value : ', r1.value.toString());
console.log('JSON.stringify(JSON.parse(input)):', JSONbig.stringify(r1));

Output:

Input: { "value" : 9223372036854775807, "v2": 123 }

node.js bult-in JSON:
JSON.parse(input).value :  9223372036854776000
JSON.stringify(JSON.parse(input)): {"value":9223372036854776000,"v2":123}


big number JSON:
JSON.parse(input).value :  9223372036854775807
JSON.stringify(JSON.parse(input)): {"value":9223372036854775807,"v2":123}