Question

How to add a range of elements of an array to another array in TypeScript

Answer 1

const source: number[] = [10, 20, 30, 40, 50, 60, 70];
let target: number[] = [1, 2, 3];
  
// Add elements from index 2 to 5 (30, 40, 50)
target.push(...source.slice(2, 5));
  
console.log(target);
  
  
  
/*
run:
  
[1, 2, 3, 30, 40, 50]
  
*/
 

 

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Answer 2

const source: number[] = [10, 20, 30, 40, 50, 60, 70];
let target: number[] = [1, 2, 3];
  
// Add elements from index 2 to 5 (30, 40, 50)
let result = target.concat(source.slice(2, 5));
  
console.log(result);
  
  
  
/*
run:
  
[1, 2, 3, 30, 40, 50] 
  
*/
 

 

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