Java – How to search a string in a List?
In Java, we can combine a normal loop and .contains()
, .startsWith()
or .matches()
to search for a string in ArrayList
.
JavaExample1.java
package com.mkyong.test;
import java.util.ArrayList;
import java.util.List;
public class JavaExample1 {
public static void main(String[] args) {
List<String> list = new ArrayList<>();
list.add("Java");
list.add("Kotlin");
list.add("Clojure");
list.add("Groovy");
list.add("Scala");
List<String> result = new ArrayList<>();
for (String s : list) {
if (s.contains("Java")) {
result.add(s);
}
/*
if (s.startsWith("J")) {
result.add(s);
}
*/
/* regex
if (s.matches("(?i)j.*")) {
result.add(s);
}
*/
}
System.out.println(result);
}
}
Output
[Java]
For Java 8, it’s much easier now.
JavaExample2.java
package com.mkyong.test;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
public class JavaExample2 {
public static void main(String[] args) {
List<String> list = new ArrayList<>();
list.add("Java");
list.add("Kotlin");
list.add("Clojure");
list.add("Groovy");
list.add("Scala");
List<String> result = list
.stream()
.filter(x -> x.contains("Java"))
.collect(Collectors.toList());
System.out.println(result);
}
}
Output
[Java]
Looks good