TypeScript Array concat() Method

The Array.concat() is an inbuilt TypeScript function that is used to merge two or more arrays. 
Syntax:

array.concat(value1, value2, ..., valueN)

Parameter: This method accepts a single parameter multiple times as mentioned above and described below: 

• valueN: These parameters are arrays and/or values to concatenate.

Return Value: This method returns the new array. 

Examples of TypeScript Array concat() Method

The below examples illustrate the Array concat() method in TypeScript.

Example 1: The TypeScript code defines three arrays, then concatenates them using the concat() method and logs the result to the console.

JavaScript

// TypeScript code
let num1: number[] = [11, 12, 13]; 
let num2: number[] = [14, 15, 16]; 
let num3: number[] = [17, 18, 19]; 
  
// Using the concat() method in TypeScript 
console.log(num1.concat(num2, num3));

Output:

[ 11, 12, 13, 14, 15, 16, 17, 18, 19 ]

Example 2: In TypeScript, define two arrays of strings, then merge them using the concat method.

JavaScript

// TypeScript code
let str1: string[] = ['a', 'b', 'c'];
let str2: string[] = ['d', 'e', 'f'];

// Using the concat() method in TypeScript
console.log(str1.concat(str2));

Output:

[ 'a', 'b', 'c', 'd', 'e', 'f' ]