The replaceAll(String) method of Matcher Class behaves as a append-and-replace method. This method reads the input string and replace it with the matched pattern in the matcher string.
Syntax:
public String replaceAll(String stringToBeReplaced)
Parameters: This method takes a parameter stringToBeReplaced which is the String to be replaced in the matcher.
Return Value: This method returns a String with the target String constructed by replacing the String.
Below examples illustrate the Matcher.replaceAll() method:
Example 1:
// Java code to illustrate replaceAll() method  import java.util.regex.*;  public class GFG {    public static void main(String[] args)    {          // Get the regex to be checked        String regex = "(Geeks)";          // Create a pattern from regex        Pattern pattern = Pattern.compile(regex);          // Get the String to be matched        String stringToBeMatched            = "GeeksForGeeks Geeks for For Geeks Geek";          // Create a matcher for the input String        Matcher matcher            = pattern.matcher(stringToBeMatched);          System.out.println("Before Replacement: "                           + stringToBeMatched);          // Get the String to be replaced        String stringToBeReplaced = "GFG";        StringBuilder builder            = new StringBuilder();          // Replace every matched pattern        // with the target String        // using replaceAll() method        System.out.println("After Replacement: "                           + matcher                                 .replaceAll(stringToBeReplaced));    }} |
Output:
Before Replacement: GeeksForGeeks Geeks for For Geeks Geek After Replacement: GFGForGFG GFG for For GFG Geek
Example 2:
// Java code to illustrate replaceAll() method  import java.util.regex.*;  public class GFG {    public static void main(String[] args)    {          // Get the regex to be checked        String regex = "(FGF)";          // Create a pattern from regex        Pattern pattern = Pattern.compile(regex);          // Get the String to be matched        String stringToBeMatched            = "GFGFGFGFGFGFGFGFGFG FGF GFG GFG FGF";          // Create a matcher for the input String        Matcher matcher            = pattern.matcher(stringToBeMatched);          // Get the String to be replaced        String stringToBeReplaced = "GFG";        StringBuilder builder            = new StringBuilder();          // Replace every matched pattern        // with the target String        // using replaceAll() method        System.out.println("After Replacement: "                           + matcher                                 .replaceAll(stringToBeReplaced));    }} |
Output:
After Replacement: GGFGGGFGGGFGGGFGGFG GFG GFG GFG GFG
Reference: https://docs.oracle.com/javase/9/docs/api/java/util/regex/Matcher.html#replaceAll-java.lang.String-
