lastIndexOf() Method in JavaScript

The lastIndexOf() method in JavaScript is used to find the index of the last occurrence of a specified value in an array.
It returns the index of the last matching element.
The search starts from the last index of the array but only shows the last occurrence.
It takes two arguments:
- search-element: The value to search for.
- from-index (optional): The index from which to start the search. If not provided, it searches from the end of the array.
If the element is not found, it returns -1.

Example:

const names = ['john', 'max', 'alex', 'tony', 'smith', 'tony', 'jack'];

To find the last occurrence of tony in the array, use the lastIndexOf() method:

const indexNo = names.lastIndexOf('tony');
console.log(indexNo);

// Output:
5

The search starts from the end of the array and returns 5 because the last occurrence of tony is at index 5.

Now, if you provide a from-index value, the search starts from that index and searches backward.

const indexNo = names.lastIndexOf('tony', 4);
console.log(indexNo);

// Output:
// 3

With from-index set to 4, the search starts from index 4 and finds the last occurrence of tony at index 3.

The lastIndexOf() method helps in finding the last occurrence of a value, optionally from a specified starting point.

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