how to use the lastindexof function from the underscore library in javascript

To use the lastIndexOf function from the underscore library in JavaScript, first we need to load the library into our project.

Assuming you have already done that, the next step is to use the function on an array. Here's an example:

index.tsx
const _ = require('underscore');

const array = [1, 2, 3, 4, 5, 4, 3, 2, 1];
const lastIndex = _.lastIndexOf(array, 4);

console.log(lastIndex); // output: 5
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In this example, we're declaring an array and then using the lastIndexOf function from the underscore library to find the index of the last occurrence of the number 4. The output will be 5, because the last occurrence of 4 in the array is at index 5.

The lastIndexOf function takes two arguments: the array to be searched and the value to search for. If the value is found in the array, the function returns the index of the last occurrence of the value. If the value is not found in the array, the function returns -1.