What is the function of the regular expression replaceFirst() method?

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The regular expression replaceFirst() methodWhat function does it have?

The following author describes the function introduction of the replaceFirst() method, as follows:

 The function of the replaceFirst() method: Use regular replacement to match the first matched string. The syntax of the replaceFirst() method: Pattern pattern = Pattern.compile("regular"); //Generate regular expression Matcher matcher = pattern.matcher("regular 122 regular 88988"); //match character matcher.replaceFirst("Java")); //replace character

Example:

package com.java265.other;import java.util.regex.Matcher;import java.util.regex.Pattern;public class testClass {/** Use of java265.com Pattern class*/public static void main(String[] args) {Pattern pattern = Pattern.compile("regular"); //Generate regular expressionMatcher matcher = pattern.matcher("regular 122 regular 88988"); //match charactersSystem.out.println(matcher.replaceFirst("Java")); // replace character}}------Run the above code, the following information will be output-----Java122 regular 88988