contains in Java?contains is a static method of the StringUtils class that checks whether a given string contains the complete search string. The complete search string should be present in the given string as it is.
The comparison is case-sensitive in nature. Refer to What is StringUtils.containsIgnoreCase in java? for case-insensitive comparison.
StringUtlisStringUtils is defined in the Apache Commons Lang package. Apache Commons Lang can be added to the Maven project by adding the following dependency to the pom.xml file.
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>
Note: For other versions of the commons-lang package, refer to the Maven Repository.
You can import the StringUtils class as follows:
import org.apache.commons.lang3.StringUtils;
public static boolean contains(CharSequence seq, CharSequence searchSeq)
The function takes in two parameters as described below.
CharSequence seq: Character sequence to search in.CharSequence searchSeq: Search sequence to search for.The function returns true if the character sequence contains a search sequence. Otherwise, it returns false.
The function will return
falsein case of a null parameter.
In the code below, we define a sequence of characters and a search string.
import org.apache.commons.lang3.StringUtils;public class Main{public static void main(String[] args){String characterSequence = "abbbcccaaaccb";String searchString = "abc";System.out.println(StringUtils.contains(characterSequence, searchString));characterSequence = "atbsljkhbv";searchString = "bsl";System.out.println(StringUtils.contains(characterSequence, searchString));}}
search string = "abc"
string = "abbbcccaaaccb"
Although the string contains the individual characters of the search string, it doesn’t contain the complete search string as it is. Hence, the function would return false.
search string = "abc"
string = "abcdefghti"
Since the string contains the complete search string (abc), the function would return true.
The output of the code will be as follows:
false
true
true because the first sequence of characters doesn’t contain the search string and false because the second sequence of characters contains the search string.