Add substring snippets

snippets/endsWithSubstring.md

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+---
+title: String ends with substring
+shortTitle: Ends with substring
+tags: string
+expertise: beginner
+cover: blog_images/boutique-home-office-4.jpg
+author: chalarangelo
+firstSeen: 2022-08-01T05:00:00-04:00
+---
+
+Checks if a given string ends with a substring of another string.
+
+- Use a `for...in` loop and `String.prototype.slice()` to get each substring of the given `word`, starting at the end.
+- Use `String.prototype.endsWith()` to check the current substring against the `text`.
+- Return the matching substring, if found. Otherwise, return `undefined`.
+
+```js
+const endsWithSubstring = (text, word) => {
+  for (let i in word) {
+    const substr = word.slice(0, i + 1);
+    if (text.endsWith(substr)) return substr;
+  }
+  return undefined;
+};
+```
+
+```js
+endsWithSubstring('Lorem ipsum dolor sit amet<br /', '<br />'); // '<br /'
+```

snippets/leftSubstrGenerator.md

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+---
+title: Left substring generator
+tags: string,generator
+expertise: intermediate
+cover: blog_images/boutique-home-office-1.jpg
+author: chalarangelo
+firstSeen: 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' ]
+```

snippets/rightSubstrGenerator.md

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+---
+title: Right substring generator
+tags: string,generator
+expertise: intermediate
+cover: blog_images/boutique-home-office-2.jpg
+author: chalarangelo
+firstSeen: 2022-07-25T05:00:00-04:00
+---
+
+Generates all right 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 end.
+
+```js
+const rightSubstrGenerator = function* (str) {
+  if (!str.length) return;
+  for (let i in str) yield str.slice(-i - 1);
+};
+```
+
+```js
+[...rightSubstrGenerator('hello')];
+// [ 'o', 'lo', 'llo', 'ello', 'hello' ]
+```

snippets/startsWithSubstring.md

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+---
+title: String starts with substring
+shortTitle: Starts with substring
+tags: string
+expertise: beginner
+cover: blog_images/boutique-home-office-3.jpg
+author: chalarangelo
+firstSeen: 2022-07-31T05:00:00-04:00
+---
+
+Checks if a given string starts with a substring of another string.
+
+- Use a `for...in` loop and `String.prototype.slice()` to get each substring of the given `word`, starting at the beginning.
+- Use `String.prototype.startsWith()` to check the current substring against the `text`.
+- Return the matching substring, if found. Otherwise, return `undefined`.
+
+```js
+const startsWithSubstring = (text, word) => {
+  for (let i in word) {
+    const substr = word.slice(-i - 1);
+    if (text.startsWith(substr)) return substr;
+  }
+  return undefined;
+};
+```
+
+```js
+startsWithSubstring('/>Lorem ipsum dolor sit amet', '<br />'); // '/>'
+```