Rename js snippets

snippets/js/s/left-substring-generator.md

@@ -0,0 +1,26 @@
+---
+title: Left substring generator
+type: snippet
+language: javascript
+tags: [string,generator]
+cover: boutique-home-office-1
+author: chalarangelo
+dateModified: 2022-07-24T05:00:00-04:00
+---
+
+Generates all left substrings of a given string.
+
+- Use `String.prototype.length` to terminate early if the string is empty.
+- Use a `for...in` loop and `String.prototype.slice()` to `yield` each substring of the given string, starting at the beginning.
+
+```js
+const leftSubstrGenerator = function* (str) {
+  if (!str.length) return;
+  for (let i in str) yield str.slice(0, i + 1);
+};
+```
+
+```js
+[...leftSubstrGenerator('hello')];
+// [ 'h', 'he', 'hel', 'hell', 'hello' ]
+```