There are multiple ways in which you can check if a Java String contains another String as a Sub-String or not, we take a look at 4 such examples.
Example 1: Using contains() method
package org.code2care.examples;
public class ExampleSubString {
public static void main(String[] args) {
String str = "This is my String!";
String subStr = "my";
if(str.contains(subStr)) {
System.out.println("String contains substring!: " + subStr);
} else {
System.out.println("String does not contain substring!: " + subStr);
}
}
}
Example 2: Using contains() with ignore case
If you want to ignore the case for the match, make both strings lower cases or upper cases while doing the check.
if(str.toLowerCase().contains(subStr.toLowerCase())) {
System.out.println("String contains substring!: " + subStr);
} else {
System.out.println("String does not contain substring!: " + subStr);
}
if(str.toUpperrCase().contains(subStr.toUpperrCase())) {
System.out.println("String contains substring!: " + subStr);
} else {
System.out.println("String does not contain substring!: " + subStr);
}
Example 3: Using Regular Expression
package org.code2care.examples;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class ExampleRegexMatch {
public static void main(String... args) {
String str = "This is my String!";
String subStr = "My";
String regexPattern = "(?i)" + Pattern.quote(subStr);
Pattern pattern = Pattern.compile(regexPattern);
Matcher matcher = pattern.matcher(str);
if (matcher.find()) {
System.out.println("String contains substring!: " + subStr);
} else {
System.out.println("String does not contain substring!: " + subStr);
}
}
}
Example 4: Using indexOf()
public static void main(String... args) {
String str = "This is my String!";
String subStr = "This";
int index = str.indexOf(subStr);
if (index != -1) {
System.out.println("String contains substring at index " + index + ": " + subStr);
} else {
System.out.println("String does not contain substring: " + subStr);
}
}
Output:
Facing issues? Have Questions? Post them here! I am happy to answer!
Author Info:
Rakesh (He/Him) has over 14+ years of experience in Web and Application development. He is the author of insightful How-To articles for Code2care.
Follow him on: X
You can also reach out to him via e-mail: rakesh@code2care.org
More Posts related to Java,
- Get the current timestamp in Java
- Java Stream with Multiple Filters Example
- Java SE JDBC with Prepared Statement Parameterized Select Example
- Fix: UnsupportedClassVersionError: Unsupported major.minor version 63.0
- [Fix] Java Exception with Lambda - Cannot invoke because object is null
- 7 deadly java.lang.OutOfMemoryError in Java Programming
- How to Calculate the SHA Hash Value of a File in Java
- Java JDBC Connection with Database using SSL (https) URL
- How to Add/Subtract Days to the Current Date in Java
- Create Nested Directories using Java Code
- Spring Boot: JDBCTemplate BatchUpdate Update Query Example
- What is CA FE BA BE 00 00 00 3D in Java Class Bytecode
- Save Java Object as JSON file using Jackson Library
- Adding Custom ASCII Text Banner in Spring Boot Application
- [Fix] Java: Type argument cannot be of primitive type generics
- List of New Features in Java 11 (JEPs)
- Java: How to Add two Maps with example
- Java JDBC Transition Management using PreparedStatement Examples
- Understanding and Handling NullPointerException in Java: Tips and Tricks for Effective Debugging
- Steps of working with Stored Procedures using JDBCTemplate Spring Boot
- Java 8 java.util.Function and BiFunction Examples
- The Motivation Behind Generics in Java Programming
- Get Current Local Date and Time using Java 8 DateTime API
- Java: Convert Char to ASCII
- Deep Dive: Why avoid java.util.Date and Calendar Classes
More Posts:
- How to Turn on/off Flashlight on iPhone - iOS
- How to read a .mat (MATLAB) file in Python - Python
- JSP Hello World Program Tutorial with Eclipse and Tomcat Server - Java
- Fix SharePoint Error - The Managed Metadata Service or Connection is currently not available. The Application Pool or Managed Metadata Web Service may not have been started - SharePoint
- How to change the default font and text size in Microsoft Excel for Mac - MacOS
- How to remove Siri from Menu Bar [macOS Big Sur] - MacOS
- How to stop/start/restart apache server using command [Ubuntu] - Ubuntu
- How to Compare Strings in Bash Script - Bash