how to use the all function from the underscore library in typescript

To use the all function from the Underscore library in TypeScript, you need to first import the Underscore library and its type definitions (if you are using TypeScript 2.0 or later). Here's how you can do it:

index.ts
import * as _ from 'underscore';

const array = [1, 2, 3, 4, 5];
const allGreaterThanZero = _.all(array, (num) => num > 0);

console.log(allGreaterThanZero); // Output: true
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In the example above, we first import the Underscore library using the import statement. We then create an array that we want to check if all its elements are greater than zero. Finally, we use the all function from Underscore to achieve that.

The all function returns true if all elements in the array pass the truth test implemented by the provided function, and false otherwise.

Note that the all function is a higher-order function that takes a function as its second argument. The function takes an array element as its argument and should return a Boolean value indicating whether the element satisfies a certain condition.