bn.js

const BN = require('bn.js'); // Initialize Big Numbers from various bases const hexValue = new BN('DEADBEEF', 16); const binValue = new BN('10101010101010101010', 2); // Decimal numbers can be large strings, exceeding standard JS Number limits const decValue = new BN('123456789012345678901234567890'); console.log('Initialized from Hex:', hexValue.toString(16)); console.log('Initialized from Binary:', binValue.toString(2)); console.log('Initialized from large Decimal String:', decValue.toString(10)); // Perform arithmetic operations let sum = hexValue.add(binValue); console.log('\nSum (hexValue + binValue) in decimal:', sum.toString(10)); let product = decValue.mul(new BN(2)); // Multiply by another BN instance console.log('Product (decValue * 2):', product.toString(10)); // Demonstrate in-place operation: `a.iadd(b)` modifies `a` let a = new BN('100', 10); let b = new BN('50', 10); a.iadd(b); console.log('In-place addition (a.iadd(b)), "a" is now:', a.toString(10)); // Should be 150 // Demonstrate unsigned modulo with negative numbers let negative = new BN('-10'); let modulo = new BN('3'); console.log('Signed modulo (-10 mod 3):', negative.mod(modulo).toString(10)); // Expected: -1 console.log('Unsigned modulo (-10 umod 3):', negative.umod(modulo).toString(10)); // Expected: 2 ((-10 % 3) + 3) // Convert to different formats (e.g., Buffer, Array) // Requires Node.js Buffer to be available in the environment for toBuffer try { const buffer = hexValue.toBuffer('be', 4); // Big-endian, 4 bytes padded console.log('Buffer representation of hexValue (hex string):', buffer.toString('hex')); } catch (e) { console.log('Buffer operations skipped (Buffer class might not be available in this environment).'); } // Check if an object is a BN.js instance console.log('\nIs hexValue a BN instance?', BN.isBN(hexValue)); console.log('Is a plain number a BN instance?', BN.isBN(123));