Merge branch 'patch-1' of https://github.com/kriadmin/30-seconds-of-code

snippets/copyToClipboard.md

@@ -0,0 +1,33 @@
+### copyToClipboard
+
+Copy a string to the clipboard. Only works as a result of user action (i.e. inside a `click` event listener).
+
+Create a new `<textarea>` element, fill it with the supplied data and add it to the HTML document.
+Use `Selection.getRangeAt()`to store the selected range (if any).
+Use `document.execCommand('copy')` to copy to the clipboard.
+Remove the `<textarea>` element from the HTML document.
+Finally, use `Selection().addRange()` to recover the original selected range (if any).
+
+```js
+const copyToClipboard = str => {
+  const el = document.createElement('textarea');
+  el.value = str;
+  el.setAttribute('readonly', '');
+  el.style.position = 'absolute';
+  el.style.left = '-9999px';
+  document.body.appendChild(el);
+  const selected =
+    document.getSelection().rangeCount > 0 ? document.getSelection().getRangeAt(0) : false;
+  el.select();
+  document.execCommand('copy');
+  document.body.removeChild(el);
+  if (selected) {
+    document.getSelection().removeAllRanges();
+    document.getSelection().addRange(selected);
+  }
+};
+```
+
+```js
+copyToClipboard('Lorem ipsum'); // 'Lorem ipsum' copied to clipboard.
+```

snippets/fibonacciUntilNum.md

@@ -17,5 +17,5 @@ const fibonacciUntilNum = num => {
 ```
 
 ```js
-fibonacciCountUntilNum(10); // 7
+fibonacciUntilNum(10); // [ 0, 1, 1, 2, 3, 5, 8 ]
 ```

snippets/isNull.md

@@ -0,0 +1,14 @@
+### isNull
+
+Returns `true` if the specified value is `null`, `false` otherwise.
+
+Use the strict equality operator to check if the value and of `val` are equal to `null`. 
+
+```js
+const isNull = val => val === null;
+```
+
+```js
+isNull(null); // true
+isNull('null'); // false
+```

snippets/isPrime.md

@@ -8,7 +8,7 @@ Return `false` if any of them divides the given number, else return `true`, unle
 ```js
 const isPrime = num => {
   const boundary = Math.floor(Math.sqrt(num));
-  for (var i = 2; i * i <= boundary; i++) if (num % i == 0) return false;
+  for (var i = 2; i <= boundary; i++) if (num % i == 0) return false;
   return num >= 2;
 };
 ```

snippets/size.md

@@ -0,0 +1,25 @@
+### size
+
+Get size of arrays, objects or strings.
+
+Get type of `value` (`array`, `object` or `string`). 
+Use `length` property for arrays. 
+Use `length` or `size` value if available or number of keys for objects. 
+Use `size` of a [`Blob` object](https://developer.mozilla.org/en-US/docs/Web/API/Blob) created from `value` for strings.
+
+Split strings into array of characters with `split('')` and return its length.
+
+```js
+const size = value =>
+  Array.isArray(value)
+    ? value.length
+    : value && typeof value === 'object'
+      ? value.size || value.length || Object.keys(value).length
+      : typeof value === 'string' ? new Blob([value]).size : 0;
+```
+
+```js
+size([1, 2, 3, 4, 5]); // 5
+size('size'); // 4
+size({ one: 1, two: 2, three: 3 }); // 3
+```

snippets/toSnakeCase.md

@@ -6,13 +6,12 @@ Break the string into words and combine them using `_` as a separator.
 For more detailed explanation of this Regex, [visit this Site](https://regex101.com/r/bMCgAB/1).
 
 ```js
-const toSnakeCase = str => {
+const toSnakeCase = str =>
   str &&
-    str
-      .match(/[A-Z]{2,}(?=[A-Z][a-z]+[0-9]*|\b)|[A-Z]?[a-z]+[0-9]*|[A-Z]|[0-9]+/g)
-      .map(x => x.toLowerCase())
-      .join('_');
-};
+  str
+    .match(/[A-Z]{2,}(?=[A-Z][a-z]+[0-9]*|\b)|[A-Z]?[a-z]+[0-9]*|[A-Z]|[0-9]+/g)
+    .map(x => x.toLowerCase())
+    .join('_');
 ```
 
 ```js

snippets/yesNo.md

@@ -0,0 +1,18 @@
+### yesNo
+
+Returns `true` if the string is `y`/`yes` or `false` if the string is `n`/`no`.
+
+Use `RegExp.test()` to check if the string evaluates to `y/yes` or `n/no`.
+Omit the second argument, `def` to set the default answer as `no`.
+
+```js
+const yesNo = (val, def = false) =>
+  /^(y|yes)$/i.test(val) ? true : /^(n|no)$/i.test(val) ? false : def;
+```
+
+```js
+yesNo('Y'); // true
+yesNo('yes'); // true
+yesNo('No'); // false
+yesNo('Foo', true); // true
+```