If you want to check if a letter is lowercase, you just have to lowercase theA-Zletters in the range. index.js functionisLowerCase(string){return/^[a-z]+$/.test(string);}console.log(isLowerCase(''));// 👉️ falseconsole.log(isLowerCase('A'));// 👉️ falseconsole.log(isLowerC...
JS Array Methods JavaScript: String toLowerCase() methodThis JavaScript tutorial explains how to use the string method called toLowerCase() with syntax and examples.Description In JavaScript, toLowerCase() is a string method that is used to convert a string to lowercase. Because the toLowerCase...
JavaScript provides two built-in functions for converting strings to uppercase and lowercase. Let us look at them. toUpperCase() Method The toUpperCase() method transforms a string into uppercase letters in JavaScript. It doesn't change the original string and returns a new string equivalent to ...
<html> <head> <title>JavaScript String toLowerCase() Method</title> </head> <body> <script> const str = "TutorialsPoint"; document.write("String str = ", str); document.write("<br>After converting a specific character '", str.charAt(9), "' into in lowercase: "); document.write(...
Convert a string to lowercase.Installation npm install @stdlib/string-base-lowercase Alternatively, To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README). If you are using Deno, visit the deno branch...
Use a for...of loop to iterate over the original array. Convert each string to uppercase or lowercase and push the strings into the new array. index.js // ✅ convert all array elements to Uppercase const arr = ['apple', 'banana', 'cereal']; const upper = []; for (const elemen...
A stringThe string converted to lowercase. Related Pages JavaScript Strings JavaScript String Methods JavaScript String Search Browser Support toLowerCase()is an ECMAScript1 (JavaScript 1997) feature. It is supported in all browsers: ChromeEdgeFirefoxSafariOperaIE ...
Test if a value is a lowercase string.Installation npm install @stdlib/assert-is-lowercase Alternatively, To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README). If you are using Deno, visit the ...
In JavaScript, you can use theArray.map()method to iterate over all elements and then use the string methods to change the case of the elements. Here is an example that demonstrates how to use theString.toUpperCase()method along withArray.map()to uppercase all elements in an array: ...
TypeError: .toLowerCase is not a function occurs when we call toLowerCase() function on object which is not an string. toLowerCase() function can be only