How to check if a string contains only alphabets and space in java regex. Classes in java. Discover practical examples and improve your Java programming skills with regex. Regex solution Regex is more powerful than String. parseInt() or Double. matches (), Pattern, and Matcher classes for complex pattern matching, validation, and manipulation of text. I don't know how to create a regular expression in JavaScript or jQuery. Jun 26, 2024 · Answer by Kynlee Xiong In order to check if a String has only unicode letters in Java, we use the isDigit () and charAt () methods with decision making statements. An alphanumeric string is a string that contains only alphabets from a-z, A-Z and some numbers from 0-9. regex package In Java, regular expressions are supported through the java. Jun 26, 2024 · Answer by Ada Santiago We can use the regex ^ [a-zA-Z]*$ to check a string for alphabets. Mar 18, 2016 · How can I check if a string contains only numbers and alphabets ie. The regex below works great, but it doesn't allow for spaces between words. Nov 20, 2024 · In Java, the matches() method in the String class checks if a string matches a specified regular expression. ,The isLetter (int codePoint) method determines whether the specific character (Unicode codePoint) is a letter. Or you use Jul 12, 2025 · Given string str, the task is to check whether the string is alphanumeric or not by using Regular Expression. I can use String's methods length () and charAt (i) as needed. Regex can be used to check a string for alphabets. regex = “ [^a-zA-Z0-9]+” where, [^a-zA-Z0-9] represents only special characters. ,We can also use the Apache Commons Lang library with the isAlpha () method in the StringUtils class that checks if the string contains only Unicode letters. + represents one or more times. I am using following regex for this: ^(?!\s*$)[-a-zA-Z ]*$ But this is allowing spaces at the beginning. As a side note, it's generally considered bad practice to compare boolean values to true or false. Jul 15, 2025 · There are various ways to check this in Java, depending on requirements. Master string validation techniques in Java. The package includes the following classes: Instead of checking that the string doesn't contain alphabetic characters, check to be sure it contains only numerics. Sep 20, 2014 · How to check whether a string contains at least one alphabet in java? Asked 12 years, 7 months ago Modified 2 years, 5 months ago Viewed 113k times Aug 5, 2013 · I want to write a simple regular expression to check if in given string exist any special character. Note that String. It validates the string by matching it to a specific pattern. contains, since you can enforce word boundary on the keywords (among other things). Implement character-by-character validation if regex is not an option. matches () method tells whether or not this string matches the given regular expression. My regex works but I don't know why it also includes all numbers, so when I put some number it r I want a regular expression that prevents symbols and only allows letters and numbers. This can be done using the matches () method of the String class, which tells whether the string matches the given regex. Jul 15, 2025 · Given string str of length N, the task is to check whether the given string contains uppercase alphabets, lowercase alphabets, special characters, and numeric values or not. ^[a-zA-Z0-9_]*$ For example, when Oct 4, 2025 · Regular Expressions, commonly known as Regex, provide a powerful way to define string patterns for searching, validating, and manipulating text in Java. It cannot contain any other special character. contains does not check for word boundary; it simply checks for substring. If you want to match other letters than A–Z, you can either add them to the character set: [a-zA-ZäöüßÄÖÜ]. Learn how to check if a string contains only letters in Java using Character. ,From Java 8 onwards, we can Solutions Use regular expressions to match a string against the pattern that permits only letters and spaces. Oct 9, 2023 · Checking if String complies with business rules is crucial for most applications. regex package to work with regular expressions. Java String API matches (String regex) Overview In this tutorial, We'll learn about Java String API matches () Method with Example programs. Here is my current code: boolean valid = true; for (char c : string. Jul 23, 2025 · Here are several methods to check if a string contains only alphabetic characters in JavaScript Using Regular Expression (/^ [A-Za-z]+$/) - Most USed The most common approach is to use a regular expression to match only alphabetic characters (both uppercase and lowercase). Now for a given string, the characters of the string are checked one by one using Regex. Example: In this example, we will check if a string contains only digits. Jul 11, 2025 · Regular Expressions are provided under java. Jan 8, 2020 · I was wondering If I could get a regular expression which will match a string that only has alphabetic characters, and that alone. contains () method, enhancing your string handling capabilities. It returns a boolean value, either true or false. toCharArray()) Java does not have a built-in Regular Expression class, but we can import the java. . regex package. Using Regular Expressions The most common and effective way to check for whitespace is by using a regular expression. For any string, here the task is to check whether a string contains only alphabets or not using Regex. The \s pattern matches any whitespace character. isLetter (), regular expressions, and handling mixed case letters. Example: The most common and straightforward approach to validate if a string contains only alphabetic characters is the regular expression. This question is similar to: Check if String contains only letters. May 22, 2012 · It should only contain alphabets and spaces between the alphabets. May 28, 2019 · 1. 1. And also will explain how this method works internally. So, something like "smith23" would not be acceptable. The idea is to have a String read and to verify that it does not contain any numeric characters. If you actually want to use the numeric value, use Integer. It cannot contain spaces at the beginning or end of the string. Often, we need to check if the name contains only allowed characters, if the email is in the correct format, or if there are restrictions on the password. matcher () in Java Print Yes if the string matches with the given regular expression. In Chinese and Japanese you will likely only encounter the ideographic space, and will never match " ". I want to write a static method that is passed a string and that checks to see if the string is made up of just letters and spaces. In simple words, First regular expression is a pattern which tells string should have only alphabetic's or . util. parseDouble() as others have explained below. It is useful for validating input patterns and searching within strings. In this article, we will learn how to use the matches() method effectively in Java with examples to illustrate its functionality. is alphanumeric? Jul 15, 2012 · We use regex because there are so many space characters around the world. In this tutorial, we’ll learn how to check if a String is alphanumeric, which can be helpful in many cases. regex package, which Jul 15, 2025 · Create the following regular expression to check if the given string contains only special characters or not. Oct 25, 2014 · I have this problem: I have a String, but I need to make sure that it only contains letters A-Z and numbers 0-9. It will check whether the exact String specified appear in the current String or not. Learn about alternatives like String. They are widely used for tasks such as email validation, password strength checking, parsing logs, and text replacement. Otherwise, print In this post we will learn how to check string contains only alphabets/letters using regex (regular expression) and apache commons StringUtils class in java. [a-zA-Z]+ matches one or more letters and ^[a-zA-Z]+$ matches only strings that consist of one or more letters only (^ and $ mark the begin and end of a string respectively). If you believe it’s different, please edit the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem. Sep 1, 2010 · Use a character set: [a-zA-Z] matches one letter from A–Z in lowercase and uppercase. Match the given string with the Regular Expression using Pattern. Any help is appreciated. Jul 23, 2025 · Here are the various methods to check if a string contains any whitespace characters using JavaScript. I want to create a regular expression that will check if a string contains only characters between a-z and A-Z with any Mar 11, 2025 · This article explores how to effectively use regex in Java's String. 2. ,Check if the String contains only unicode letters or digits in Java Dec 12, 2019 · It doesn't work with regex. Trim the string first to remove any leading or trailing whitespace before performing the check. ekmyr js8as 3e76h rm pleo3iv mhpgu ile6 6ld0h3 sq3v 6m0qc