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isEqual

Deeply compares two values for equality, handling objects, arrays, dates, regex, maps, sets, symbols, and BigInt.

Usage Scenarios

  • Data Comparison: Compare complex objects or arrays for deep equality.
  • State Management: Check if state has changed before triggering updates.
  • Testing: Verify expected and actual values match in tests.

Examples

import { isEqual } from 'funtool';

// Comparing primitive values
isEqual(5, 5); // ✅ true
isEqual(5, '5'); // ❌ false

// Comparing arrays (ordered)
isEqual([1, 2, 3], [1, 2, 3]); // ✅ true
isEqual([1, 2, 3], [3, 2, 1]); // ❌ false (default ordered=true)

// Comparing arrays (unordered)
isEqual([1, 2, 3], [3, 2, 1], { ordered: false }); // ✅ true

// Comparing objects
isEqual({ a: 1, b: 2 }, { b: 2, a: 1 }); // ✅ true
isEqual({ a: 1, b: 2 }, { a: 1, b: 3 }); // ❌ false

// Comparing Dates
isEqual(new Date('2025-05-01'), new Date('2025-05-01')); // ✅ true
isEqual(new Date('2025-05-01'), new Date('2025-05-02')); // ❌ false

Signature

function isEqual(
  a: any,
  b: any,
  options: boolean | { ordered: boolean } = true,
  seen: WeakMap<object, object> = new WeakMap()
): boolean

Parameters

  • a (any): The first value to compare.
  • b (any): The second value to compare.
  • options (boolean | { ordered: boolean }): If true, arrays are compared in order, otherwise unordered. Default: true.
  • seen (WeakMap<object, object>): A map used to track circular references during comparison.

Returns

  • (boolean): Returns true if the values are deeply equal, false otherwise.
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