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

You can use the _.size function from the Underscore.js library to get the number of elements in an array or an object. Here is an example:

index.tsx
var numbers = [1, 2, 3, 4, 5];
var size = _.size(numbers);
console.log(size); // Output: 5

var person = { name: 'John', age: 30, gender: 'male' };
var size = _.size(person);
console.log(size); // Output: 3
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In the first example, we have an array of numbers and we use _.size to get the number of elements in the array, which is 5.

In the second example, we have an object representing a person, and we use _.size to get the number of properties in the object, which is 3.

As you can see, _.size is a useful function to have when working with arrays and objects in JavaScript.