Home >Java >JavaBase >What are the methods in Java to determine whether a string contains a specific string?

What are the methods in Java to determine whether a string contains a specific string?

王林
王林Original
2019-11-30 10:55:3516884browse

What are the methods in Java to determine whether a string contains a specific string?

N ways to determine whether a string contains a certain substring:

1, startsWith()method

2. contains()method

3.indexOfmethod

startsWith() method

There are two variants of this method that detect whether a string starts with a specified prefix.

The syntax defined by this method is as follows:

public boolean startsWith(String prefix, int toffset)
or
public boolean startsWith(String prefix)

Parameter description:

prefix – The prefix to be matched.

toffset – Where to start looking for the string.

Return value:

true and false

Related video tutorial recommendation: java learning video

Example:

import java.io.*;
 
public class Test{
   public static void main(String args[]){
      String Str = new String("Welcome to Yiibai.com");
 
      System.out.print("Return Value :" );
      System.out.println(Str.startsWith("Welcome") );
 
      System.out.print("Return Value :" );
      System.out.println(Str.startsWith("Tutorials") );
 
      System.out.print("Return Value :" );
      System.out.println(Str.startsWith("Yiibai", 11) );
   }
}

contains method

java.lang.String.contains()

method returns true if and only if this string contains the specified sequence of char values.

Return value:

true and false

Examples are as follows:

public static void main(String[] args) {
 
        String str = "abc";
 
        boolean status = str.contains("a");
 
        if(status){
            System.out.println("包含");
 
        }else{
            System.out.println("不包含");
        }
 
    }

indexOf method

java.lang.String.indexOf()

The purpose is to find the position of a word in a string, and also to determine whether a string contains a certain character.

Return value:

int

The example is as follows:

public static void main(String[] args) {
    String str1 = "abcdefg";
    int result1 = str1.indexOf("ab");
    if(result1 != -1){
        System.out.println("字符串str中包含子串“ab”"+result1);
    }else{
        System.out.println("字符串str中不包含子串“ab”"+result1);
    }
}

For more related tutorials, please visit: java introductory learning

The above is the detailed content of What are the methods in Java to determine whether a string contains a specific string?. For more information, please follow other related articles on the PHP Chinese website!

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn