In this article, we are going to learn about checking if a string contains only alphabetic characters in JavaScript.Checking if a string contains only alphabetic characters means verifying that all characters within the string are letters of the alphabet (A-Z or a-z) and do not include any digits, symbols, or other non-alphabetic characters.
There are some common methods that can be used to check if a string contains only alphabetic characters in JavaScript, which are listed below:
Table of Content
We will explore all the above methods along with their basic implementation with the help of examples.
Approach 1: Using a Regular Expression
To check if a string contains only alphabetic characters in JavaScript, use the regular expression /^[a-zA-Z]+$/. It returns true if the string consists solely of letters, and false otherwise.
Syntax:
let regex = /^[a-zA-Z]+$/;
Example: In this example, the regular expression ^[a-zA-Z]+$ tests if a string consists only of alphabetic characters (letters). The code validates str1 as true and str2 as false.
Javascript
let str1 = "neveropen"; let str2 = "Geeks123"; let regex = /^[a-zA-Z]+$/; console.log(regex.test(str1)); console.log(regex.test(str2)); |
true false
Approach 2: Using for of loop
In this approach, we are using for…of loop to iterate through each character in the input string. It returns true if all characters are alphabetic (A-Z or a-z), otherwise false.
Syntax:
for ( variable of iterableObjectName) {
...
};
Example: In this example, checkAlphabets function iterates through each character in the input string and returns true if all characters are alphabetic (A-Z or a-z), otherwise false.
Javascript
function checkAlphabets(input) { for (const char of input) { if (!(char >= "a" && char <= "z") && !(char >= "A" && char <= "Z")) { return false; } } return true; } const str1 = "neveropen"; const str2 = "Geeks123"; console.log(checkAlphabets(str1)); console.log(checkAlphabets(str2)); |
true false
