JavaScript Array concat() method is used to merge two or more arrays.
It does not change the existing array.
Syntax
array1.concat(array2, array3, ..., arrayX)Parameters
array1(required): The array to which other arrays will be concatenated.
Return value
Returns a new array which is the content from the joined arrays.
Visual Representation
Example 1: How to Use Array concat() Method
let data1 = ['Apple', 'Google', 'OpenAI'];
let data2 = ['LV', 'Zara', 'HNM'];
let result = data1.concat(data2);
console.log(result);Output
[ 'Apple', 'Google', 'OpenAI', 'LV', 'Zara', 'HNM' ]Example 2: Concatenating three Arrays
let data1 = ['Apple', 'Google', 'OpenAI'];
let data2 = ['LV', 'Zara','HNM'];
let data3 = ['BMW', 'Mercedes', 'Audi'];
let result = data1.concat(data2,data3);
console.log(result);Output
[ 'Apple', 'Google', 'OpenAI', 'LV', 'Zara', 'HNM', 'Mercedes', 'Audi' ]Example 3: Concatenating nested arrays
let arr1 = [10, 20, [30, 40]];
let arr2 = [50, [60, 70]];
let nested_arr = arr1.concat(arr2);
console.log(result);Output
[ 10, 20, [ 30, 40 ], 50, [ 60, 70 ] ]Example 4: Using sparse arrays
console.log([10, , 30].concat([50, 60]));
console.log([10, 20].concat([50, , 70]));
Output
[ 10, <1 empty item>, 30, 50, 60 ]
[ 10, 20, 50, <1 empty item>, 70 ]
Example 5: Calling concat() on non-array objects
console.log(Array.prototype.concat.call({}, 20, 30, 40));
console.log(Array.prototype.concat.call(1, 2, 3));
Output
[ {}, 11, 21, 19 ]
[ [Number: 1], 2, 3 ]Browser Compatibility
- Google Chrome 1 and above
- Edge 12 and above
- Firefox 1 and above
- Opera 4 and above
- Safari 1 and above
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