Understanding JavaScript Array Const

Using Const with Arrays

JavaScript const arrays prevent reassignment, allowing method mutations.

Introduction to JavaScript Array Const

In JavaScript, the const keyword is used to declare variables whose values are meant to remain constant after assignment. However, when working with arrays, using const has a slightly different implication. While the reference to the array cannot be reassigned, the contents of the array can still be modified using array methods.

Declaring a Constant Array

Declaring an array with const means that once the array is initialized, the variable identifier cannot be reassigned to a different array or value. However, this does not make the array immutable.

Modifying Array Elements

Although the array reference is constant, you can still modify the elements within the array. This includes adding, removing, or changing elements using array methods such as push(), pop(), shift(), unshift(), etc.

Attempting Reassignment

If you attempt to reassign a const array to a new array or a different value, JavaScript will throw a TypeError. This restriction is what makes the reference constant, ensuring the variable identifier always points to the same array.

Conclusion

Using const with arrays in JavaScript allows you to maintain a constant reference to an array while still being able to modify its contents. This is useful for scenarios where you need a stable reference to a collection of data that may frequently change.

JS Array Const