freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/functional-programming/combine-two-arrays-using-the-concat-method/index.md

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title: Combine Two Arrays Using the concat Method
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# Combine Two Arrays Using the concat Method


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## Hints

### Hint 1
- The concat method is used to join two or more arrays or strings.

### Hint 2
- This method does not mutate the existing arrays, but returns a new array.


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## Solutions

<details><summary>Solution 1 (Click to Show/Hide)</summary>

```javascript
function nonMutatingConcat(original, attach) {
  // Add your code below this line

  return original.concat(attach);

  // Add your code above this line
}
var first = [1, 2, 3];
var second = [4, 5];
nonMutatingConcat(first, second);
```
</details>