Definition:
'unshift' is a JavaScript method that adds one or more elements to the beginning of an array.
How to Use Unshift:
- Declare an Array: Create an array using square brackets [].
- Apply Unshift: Call the 'unshift' method on the array and pass the elements to be added as arguments.
Example:
let numbers = [2, 4, 6];
numbers.unshift(0, 1); // Adds 0 and 1 to the beginning
// Result: [0, 1, 2, 4, 6]
Key Concepts:
- Elements: The elements to be added to the beginning of the array.
- Modifies Original Array: 'unshift' modifies the original array, unlike slicing methods like 'slice' which create a new copy.
- Returns New Length: The 'unshift' method returns the new length of the modified array.
Tips:
- You can add multiple elements at once by passing them as individual arguments.
- 'unshift' operates on arrays only. For other data structures like strings, you can use 'splice' to insert elements.
Conclusion:
'unshift' is a useful method for conveniently adding elements to the beginning of an array. It is simple to use and modifies the original array directly.