merge

Merge multiple arrays into one array, with optional deduplication.

Basic Usage

import { merge } from 'radash'

const array1 = [1, 2, 3]
const array2 = [4, 5, 6]
const array3 = [7, 8, 9]

const merged = merge(array1, array2, array3)
// [1, 2, 3, 4, 5, 6, 7, 8, 9]

Syntax

function merge<T>(
  ...arrays: readonly T[][]
): T[]

Parameters

• ...arrays (readonly T[][]): Arrays to merge, can pass any number of arrays

Return Value

Returns a merged array containing all elements from the input arrays.

Examples

Basic Merge

import { merge } from 'radash'

const fruits = ['apple', 'banana']
const vegetables = ['carrot', 'lettuce']
const grains = ['rice', 'wheat']

const allFood = merge(fruits, vegetables, grains)
// ['apple', 'banana', 'carrot', 'lettuce', 'rice', 'wheat']

Merging Object Arrays

import { merge } from 'radash'

const users1 = [
  { id: 1, name: 'Alice' },
  { id: 2, name: 'Bob' }
]

const users2 = [
  { id: 3, name: 'Charlie' },
  { id: 4, name: 'Diana' }
]

const allUsers = merge(users1, users2)
// [
//   { id: 1, name: 'Alice' },
//   { id: 2, name: 'Bob' },
//   { id: 3, name: 'Charlie' },
//   { id: 4, name: 'Diana' }
// ]

Merging Different Types of Arrays

import { merge } from 'radash'

const numbers = [1, 2, 3]
const strings = ['a', 'b', 'c']
const booleans = [true, false]

const mixed = merge(numbers, strings, booleans)
// [1, 2, 3, 'a', 'b', 'c', true, false]

Merging Empty Arrays

import { merge } from 'radash'

const empty1: number[] = []
const empty2: number[] = []
const numbers = [1, 2, 3]

const result = merge(empty1, numbers, empty2)
// [1, 2, 3]

Merging Single Array

import { merge } from 'radash'

const numbers = [1, 2, 3]
const result = merge(numbers)
// [1, 2, 3]

Merging Nested Arrays

import { merge } from 'radash'

const array1 = [[1, 2], [3, 4]]
const array2 = [[5, 6], [7, 8]]

const merged = merge(array1, array2)
// [[1, 2], [3, 4], [5, 6], [7, 8]]

Comparison with Spread Operator

import { merge } from 'radash'

const array1 = [1, 2, 3]
const array2 = [4, 5, 6]

// Using merge
const merged1 = merge(array1, array2)
// [1, 2, 3, 4, 5, 6]

// Using spread operator
const merged2 = [...array1, ...array2]
// [1, 2, 3, 4, 5, 6]

Dynamic Merging

import { merge } from 'radash'

function combineArrays<T>(...arrays: T[][]) {
  return merge(...arrays)
}

const result = combineArrays(
  [1, 2],
  [3, 4],
  [5, 6]
)
// [1, 2, 3, 4, 5, 6]

Notes

1. Keep original arrays unchanged: merge does not modify the original arrays, but returns a new array
2. Order: The merged array is arranged in the order of the input arrays
3. Empty array handling: Empty arrays are ignored and do not affect the result
4. Performance: Time complexity is O(n), where n is the total length of all arrays
5. Memory: Will create a new array, pay attention to memory usage

Differences from Other Methods

• concat(): Can only merge two arrays, requires chaining calls
• spread operator: Same functionality, but different syntax
• merge(): More intuitive API provided by radash, supports multiple arrays

Practical Application Scenarios

1. Data integration: Merge data from different sources
2. Configuration merging: Merge multiple configuration arrays
3. API responses: Merge results from multiple API calls
4. File processing: Merge content from multiple files
5. Cache management: Merge multiple cache arrays