How do you remove a non-alphanumeric character from a string?

Using Regular Expression We can use the regular expression [^a-zA-Z0-9] to identify non-alphanumeric characters in a string. Replace the regular expression [^a-zA-Z0-9] with [^a-zA-Z0-9 _] to allow spaces and underscore character.

How do you replace non-alphanumeric characters with empty strings?

The approach is to use the String. replaceAll method to replace all the non-alphanumeric characters with an empty string.

How do I remove all characters from a string in Java?

In the following example, the removeAll() method removes all the special characters from the string and puts a space in place of them.

public class RemoveSpecialCharacterExample1.
{
public static void main(String args[])
{
String str= “This#string%contains^special*characters&.”;
str = str.replaceAll(“[^a-zA-Z0-9]”, ” “);

How do you delete characters from alphanumeric strings?

str = str. replaceAll(“[^\\d]”, “”); You can try this java code in a function by taking the input value and returning the replaced value as per your requirement. Hope this will help you to achieve your requirement.

How do you remove non alphabetic characters from a string in C++?

Algorithm to Delete non Alphabet characters from String

Initialize two variables i and j to 0 and -1 respectively.
Using a loop, traverse the inputString from index i=0 to i=N-1.
For every character inputString[i],check if it is an alphabet character.
After the end of for loop, set inputString[j] = ‘\0’.

How do you replace all non-alphanumeric character with empty string provide answer using regex?

13 Answers

Neither should the space at the end of the character class.
the reg exp is ok, just remove “/” from the regexp string from value.replaceAll(“/[^A-Za-z0-9 ]/”, “”); to value.replaceAll(“[^A-Za-z0-9 ]”, “”); you don’t need the “/” inside the regexp, I think you’ve confused with javascript patterns.

What are the non-alphanumeric characters?

Non-Alphanumeric characters are the other characters on your keyboard that aren’t letters or numbers, e.g. commas, brackets, space, asterisk and so on. Any character that is not a number or letter (in upper or lower case) is non-alphanumeric. These could be grouped as Punctuation characters !

How do I remove all characters from a string?

Using ‘str. replace() , we can replace a specific character. If we want to remove that specific character, replace that character with an empty string. The str. replace() method will replace all occurrences of the specific character mentioned.

How do you replace a non alphanumeric character in Java?

replaceAll() method. A common solution to remove all non-alphanumeric characters from a String is with regular expressions. The idea is to use the regular expression [^A-Za-z0-9] to retain only alphanumeric characters in the string. You can also use [^\w] regular expression, which is equivalent to [^a-zA-Z_0-9] .

How do you remove a character from a character array in Java?

Approach:

Get the array and the index.
Form an ArrayList with the array elements.
Remove the specified index element using remove() method.
Form a new array of the ArrayList using mapToInt() and toArray() methods.
Return the formed array.