Check if None of the Strings in the List Matches a Condition in Java

In this article, you will learn how to check if none of the strings in a list start with a specific letter using Java. This approach is useful for validating or filtering data. We will use the Stream API to evaluate the condition and return a boolean result based on whether any string starts with the given letter.

Problem Statement

Write a program in Java to check if none of the strings in the list matches the condition.

Input

pqr,stu,vwx,yza,vwxy

Output

No match for the starting letter as f? = true

Steps to check if none of the string matches the condition

Following are the steps to check if none of the string matches the condition

• First, we will import ArrayList and List from the java.util package.
  
• Create a list using the ArrayList class, we will create a list of strings.
  
• Use the Stream API by calling the stream() method to work with the list as a stream.
  
• Apply the noneMatch() method by using noneMatch() to check if none of the strings start with the specified letter.
  
• At the end, the boolean result will be printed to the console.
  

Java program to check if none of the string matches the condition

The following is an example to check if none of the string in the list matches the condition

import java.util.ArrayList;
import java.util.List;
public class Demo {
   public static void main(final String[] args) {
      List<String> myList = new ArrayList<>();
      myList.add("pqr");
      myList.add("stu");
      myList.add("vwx");
      myList.add("yza");
      myList.add("bcd");
      myList.add("efg");
      myList.add("vwxy");
      boolean res = myList.stream().noneMatch((a) -> a.startsWith("f"));
      System.out.println("No match for the starting letter as f? = "+res);
   }
}

Output

No match for the starting letter as f? = true

Code explanation

In the above program, we create a list of strings using the ArrayList class and populate it with several string values. The stream() method is called on the list, enabling us to use the noneMatch() method from the Stream API. This method checks if none of the strings in the list start with the letter 'f'. If this condition holds true for all elements, the method returns true; otherwise, it returns false. The result is then printed to the console, showing whether any string starts with 'f'.