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

_.findIndex is a function in the Underscore library that is used to find the index of the first element in an array that matches the given condition.

Here is the syntax for using _.findIndex:

index.tsx
_.findIndex(array, predicate, [context])
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• array (Array): The array to search.
• predicate (Function): The function to apply to each element in the array. The function should return a boolean value indicating whether the element satisfies the condition.
• [context] (Object): The context to use as this when executing the predicate function.

Example usage:

index.tsx
var numbers = [1, 2, 3, 4, 5];

// Find the index of the first even number in the array
var evenIndex = _.findIndex(numbers, function(num) {
  return num % 2 === 0;
});

console.log(evenIndex); // Output: 1
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In the example above, the _.findIndex function is called on the numbers array with a predicate function that checks whether each number is even or odd. The function returns the index of the first even number, which is 1.