Sometimes, we want to combine 2 JavaScript arrays by concatenating them into one array.
In this article, we’ll look at how to join or combine 2 JavaScript arrays by concatenating them into one array.
Use the Array.prototype.concat Method
One way to join 2 Javascript arrays by concatenating them into one array is to use the JavaScript array’s concat method.
For instance, we can write:
const a = ['a', 'b', 'c'];
const b = ['d', 'e', 'f'];
const c = a.concat(b);
console.log(c)
We call a.concat(b) to add the entries of b after the entries of a and return the new array with all the entries.
Therefore, c is:
["a", "b", "c", "d", "e", "f"]
Use the Spread Operator
Another way to combine 2 arrays by joining them together is to use the spread operator.
For example, we can write:
const a = ['a', 'b', 'c'];
const b = ['d', 'e', 'f'];
const c = [...a, ...b]
console.log(c)
We spread the entries of a and b into a new array to form the c array.
They’ll be spread in the same order that they’re listed.
Therefore, c is now:
["a", "b", "c", "d", "e", "f"]
Conclusion
We can use the JavaScript array’s concat method or the spread operator to combine 2 JavaScript arrays by joining them together.
