Equality Utilities

The Equality utilities provide functions for comparing values and objects in JavaScript. These functions offer more comprehensive equality checks than the built-in equality operators, particularly for complex data structures.

Functions

isEqual

function isEqual(a, b, options?)

Performs a deep equality comparison between two values.

Deep Comparison This function performs a recursive comparison for objects and arrays, ensuring that nested structures are also checked for equality. It handles various edge cases, including NaN comparisons.

Parameters

Name	Type	Description
a	any	The first value to compare
b	any	The second value to compare
options	object	Optional comparison options

Options

Name	Type	Default	Description
loose	boolean	`false`	Uses `==` instead of `===` for leaf value comparison
ignoreKeys	string[]	`[]`	Array of property names to skip during comparison
partial	boolean	`false`	Checks if `a` is a structural subset of `b`

Returns

boolean - true if the values are deeply equal, false otherwise.

Example

import { isEqual } from '@semantic-ui/utils';

console.log(isEqual({a: 1, b: {c: 2}}, {a: 1, b: {c: 2}})); // true
console.log(isEqual([1, 2, 3], [1, 2, 3])); // true
console.log(isEqual({a: 1, b: 2}, {b: 2, a: 1})); // true
console.log(isEqual(NaN, NaN)); // true
console.log(isEqual({a: 1, b: 2}, {a: 1, b: 3})); // false

Loose Comparison

When loose is true, leaf values are compared with == instead of ===, allowing type coercion.

import { isEqual } from '@semantic-ui/utils';

console.log(isEqual('1', 1, { loose: true })); // true
console.log(isEqual(0, false, { loose: true })); // true
console.log(isEqual('1', 1)); // false (strict by default)

Ignoring Keys

Use ignoreKeys to skip specific properties during comparison.

import { isEqual } from '@semantic-ui/utils';

const a = { name: 'Alice', updatedAt: 1000 };
const b = { name: 'Alice', updatedAt: 2000 };

console.log(isEqual(a, b)); // false
console.log(isEqual(a, b, { ignoreKeys: ['updatedAt'] })); // true

Partial Comparison

When partial is true, checks if a is a structural subset of b — every key in a must exist and match in b, but b may have additional keys.

import { isEqual } from '@semantic-ui/utils';

const subset = { a: 1 };
const full = { a: 1, b: 2, c: 3 };

console.log(isEqual(subset, full)); // false
console.log(isEqual(subset, full, { partial: true })); // true
console.log(isEqual(full, subset, { partial: true })); // false (a has keys b doesn't)

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