How to merge two arrays in angular and typescript?

We will see how to merge one or more arrays using TypeScript. The concat() method returns a new array by concatenating two or more arrays, while the spread operator creates a new array by spreading the elements of the input arrays. We can use the concat() method or the spread operator (…) to merge the arrays; see the examples below.

1. Using the concat() method to merge one or more arrays and return to the new array:

   let array1 = [1, 2, 3];
   let array2 = [4, 5, 6];
   let array3 = [7, 8, 9];
   let mergedArray = array1.concat(array2, array3);
   console.log(mergedArray); // [1, 2, 3, 4, 5, 6]
   

2. Using the spread operator to merge the arrays and return the output:

   let array1 = [1, 2, 3];
   let array2 = [4, 5, 6];
   let mergedArray = [...array1, ...array2];
   console.log(mergedArray); // [1, 2, 3, 4, 5, 6]
   

3. Using the spread operator to merge the new array with the existing array:

   let array1 = [1, 2, 3];
   let array2 = [4, 5, 6];
   array1.push(...array2);
   console.log(array1); // [1, 2, 3, 4, 5, 6]