# Introduction In this lab, we will explore how to generate all left substrings of a given string using JavaScript. We will create a `leftSubstrGenerator` function that uses a `for...in` loop and `String.prototype.slice()` to yield each substring of the given string, starting at the beginning. By the end of this lab, you will have a solid understanding of how to generate left substrings of any given string in JavaScript.
Click the virtual machine below to start practicing