Check if a character is a digit

adriancbo · Oct 22, 2021 · 361f1c1 · 361f1c1
1 parent 3ee1d0a
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Showing 1 changed file with 40 additions and 0 deletions.
diff --git a/snippets/validator/check-if-a-character-is-a-digit.md b/snippets/validator/check-if-a-character-is-a-digit.md
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+---
+title: Check if a character is a digit
+category: Validator
+---
+
+**JavaScript version**
+
+```js
+const isDigit = (char) => char < 10;
+
+// Or
+const isDigit = (char) => char.length === 1 && c >= '0' && c <= '9';
+
+// Or
+const isDigit = (char) => Boolean([true, true, true, true, true, true, true, true, true, true][char]);
+```
+
+**TypeScript version**
+
+```js
+const isDigit = (char: string): boolean => char < 10;
+
+// Or
+const isDigit = (char: string): boolean => char.length === 1 && c >= '0' && c <= '9';
+
+// Or
+const isDigit = (char: string): boolean => Boolean([true, true, true, true, true, true, true, true, true, true][char]);
+```
+
+**Examples**
+
+```js
+isDigit('a'); // false
+isDigit('abc'); // false
+isDigit(10); // false
+isDigit('10'); // false
+
+isDigit('2'); // true
+isDigit(2); // true
+```