With this example we are going to demonstrate how to get all digits from a String, using a regular expression. In short, to get all digits from a String you should:
- Use a given String with letters and digits.
- Use
replaceAll(String regex, String replacement)API method of String, with a given regular expression and a String to be used as replacement. The regular expression is constructed by a digit and the replacement String is an empty String. The method replaces each substring of this string that matches the given regular expression with the given replacement. An invocation of this method of the formstr.replaceAll(regex, repl)yields exactly the same result as the expressionjava.util.regex.Pattern.compile(regex).matcher(str).replaceAll(repl).
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
public class Main {
public static void main(String[] argv) throws Exception {
System.out.println("abasdfasdf1 2wasdfasdf9_8asdfasdfz asdfasdfyx7".replaceAll("\\D", ""));
}
}
Output:
12987
This was an example of how to get all digits from a String in Java.
