The push() method is used to add one or more elements to the end of an array. The return value for the push() method is the new length of the array. Here’s an example of adding a new fruit to the existing fruits array:
const fruits = ["apple", "banana"];
const newLength = fruits.push("orange");
console.log(newLength); // 3
console.log(fruits); // ["apple", "banana", "orange"]In this example, we start with an array called fruits which contains two elements. We then use the push() method to add the string orange to the end of the array.
You might have noticed that we are using const when declaring the fruits array. But why is it possible to add more elements to this fruits array when fruits is a constant? This is possible because declaring an array with the const keyword creates a reference to the array. While the array itself is mutable and can be modified, you cannot reassign a new value to the fruits constant, like this:
const fruits = ["apple", "banana"];
fruits = ["This", "will", "not", "work"];
console.log(fruits); // Uncaught TypeError: Assignment to constant variable.