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Java String contains() usage and example

Java String (String) Methods

The String contains() method checks whether the specified string (character sequence) exists in the string.

The syntax of the String contains() method is:

string.contains(CharSequence str)

contains() parameter

The contains() method takes a single parameter.

  • str (charSequence)-Character sequence

Note: charSequence is a character sequence, for example: String, CharBuffer, StringBuffer, etc.

contains() return value

  • If the string contains the specified string str, thenReturns true

  • If the string does not contain the specified string str, thenReturns false

Example1: Java string contains()

class Main {
　　public static void main(String[] args) {
　　　　String str1　= "Learn Java";
　　　　Boolean result;
　　　　//Check str1Whether it contains "Java"
　　　　result = str1.contains("Java");
　　　　System.out.println(result);　//　true
　　　　//Check str1Whether it contains "Python"
　　　　result = str1.contains("Python");
　　　　System.out.println(result);　//　false
　　　　//Check str1Whether it contains ""
　　　　result = str1.contains(
　　　　System.out.println(result);　//　true
　　}
}

Here, string.contains(

Example2: Use contains() with if ... else together

class Main {
　　public static void main(String[] args) {
　　　　String str1　= "Learn Java";
　　　　String str2　= "Java";
　　　　String str3　= "java";
　　　　Boolean result;
　　　　
　　　　//　returns true because "Learn Java" includes "Java"
　　　　if (str1.contains(str2)) {
　　　　　　System.out.println(str1　+　" Does Include "　+　str2);
　　　　}
　　　　else {
　　　　　　System.out.println(str1　+　" Does Not Include "　+　str2);
　　　　}
　　　　
　　　　//　contains() is case-sensitive
　　　　//　returns false because "Learn Java" does not include "java"
　　　　if (str1.contains(str3)) {
　　　　　　System.out.println(str1　+　" Does Include "　+　str3);
　　　　}
　　　　else {
　　　　　　System.out.println(str1　+　" Does Not Include "　+　str3);
　　　　}
　　}
}

Output Result

Learn Java Includes Java　　　　　　　　　　　　
Learn Java Does Not Include

Java String (String) Methods

Java Method OverloadingComprehensive Java String Methods