Java 8 – How to check whether a number exists in an Arrays or List or Stream ?

In this article, we will learn how to check whether a particular number exists in an Arrays or List or Stream using Java 8 Stream

1. Find a number in an Arrays :

We will find a particular number in an Arrays using Java 7 and Java 8 version –

  • Using Java 1.7 version
  • Using Java 8 Stream

1.1 Using Java 1.7 version :

  • Initially, there is a Integer[] Arrays consisting of 10 integer numbers between 1 to 99
  • For finding particular number from an Arrays
    • First, convert Arrays to List using Arrays.asList() method
    • Then use contains() method of List by passing number to be find which will return result in the form of boolean either true/false
  • Finally, print the result to the console

FindNumberInAnArraysUsingJava.java

package in.bench.resources.arrays.find.number;

import java.util.Arrays;
import java.util.List;

public class FindNumberInAnArraysUsingJava {

	public static void main(String[] args) {

		// local variable
		Boolean boolFind = false;


		// 1. Integer[] Arrays
		Integer[] numbers = new Integer[] {
				97, 2, 19, 63, 23, 86, 55, 93, 21, 99
		};


		// 2. Convert Integer[] Arrays to List of Integer
		List<Integer> numberList = Arrays.asList(numbers);
		System.out.println("Orginal Integer[] Arrays :- \n" 
				+ Arrays.toString(numbers) + "\n");


		// 2.1 find particular number 93
		boolFind = numberList.contains(93);
		System.out.println("Number (93) present in Integer[] Arrays :- " + boolFind);


		// 2.2 find particular number 86
		boolFind = numberList.contains(86);
		System.out.println("Number (86) present in Integer[] Arrays :- " + boolFind);


		// 2.3 find particular number 55
		boolFind = numberList.contains(55);
		System.out.println("Number (55) present in Integer[] Arrays :- " + boolFind);


		// 2.4 find particular number 16
		boolFind = numberList.contains(16);
		System.out.print("Number (16) present in Integer[] Arrays :- " + boolFind);
	}
}

Output:

Orginal Integer[] Arrays :- 
[97, 2, 19, 63, 23, 86, 55, 93, 21, 99]

Number (93) present in Integer[] Arrays :- true
Number (86) present in Integer[] Arrays :- true
Number (55) present in Integer[] Arrays :- true
Number (16) present in Integer[] Arrays :- false

1.2 Using Java 8 Stream :

  • Initially, there is a Integer[] Arrays consisting of 10 integer numbers between 1 to 99
  • For finding particular number from an Arrays using Java 8 Stream
    • Get Stream from Arrays using Arrays.stream() method by passing Integer[] Arrays
    • Then invoke anyMatch() method of Stream and check whether number exists in an Arrays using equals() method by passing number to be find which will return result in the form of boolean either true/false
  • Finally, print the result to the console

FindNumberInAnArraysUsingJava8.java

package in.bench.resources.arrays.find.number;

import java.util.Arrays;

public class FindNumberInAnArraysUsingJava8 {

	public static void main(String[] args) {

		// local variable
		Boolean boolFind = false;


		// Integer[] Arrays
		Integer[] numbers = new Integer[] {
				97, 2, 19, 63, 23, 86, 55, 93, 21, 99
		};
		System.out.println("Orginal Integer[] Arrays :- \n" 
				+ Arrays.toString(numbers) + "\n");


		// 1. find particular number 93
		boolFind = Arrays.stream(numbers).anyMatch(number -> number.equals(93));
		System.out.println("Number (93) present in Integer[] Arrays :- " + boolFind);


		// 2. find particular number 86
		boolFind = Arrays.stream(numbers).anyMatch(number -> number.equals(86));
		System.out.println("Number (86) present in Integer[] Arrays :- " + boolFind);


		// 3. find particular number 55
		boolFind = Arrays.stream(numbers).anyMatch(number -> number.equals(55));
		System.out.println("Number (55) present in Integer[] Arrays :- " + boolFind);


		// 4. find particular number 16
		boolFind = Arrays.stream(numbers).anyMatch(number -> number.equals(16));
		System.out.print("Number (16) present in Integer[] Arrays :- " + boolFind);
	}
}

Output:

Orginal Integer[] Arrays :- 
[97, 2, 19, 63, 23, 86, 55, 93, 21, 99]

Number (93) present in Integer[] Arrays :- true
Number (86) present in Integer[] Arrays :- true
Number (55) present in Integer[] Arrays :- true
Number (16) present in Integer[] Arrays :- false

2. Find a number in a List or ArrayList :

We will find a particular number in a List/ArrayList using Java 7 and Java 8 version –

  • Using Java 1.7 version
  • Using Java 8 Stream

2.1 Using Java 1.7 version :

  • Initially, there is a Integer List consisting of 10 integer numbers between 1 to 99
  • For finding particular number from a List or ArrayList
    • Directly use/invoke contains() method of List by passing number to be find which will return result in the form of boolean either true/false
  • Finally, print the result to the console

FindNumberInListUsingJava.java

package in.bench.resources.arrays.find.number;

import java.util.ArrayList;
import java.util.List;

public class FindNumberInListUsingJava {

	public static void main(String[] args) {

		// local variable
		Boolean boolFind = false;


		// 1. Integer List
		List<Integer> numberList = new ArrayList<Integer>();


		// 2. add numbers to List
		numberList.add(97);
		numberList.add(2);
		numberList.add(19);
		numberList.add(63);
		numberList.add(23);
		numberList.add(86);
		numberList.add(55);
		numberList.add(93);
		numberList.add(21);
		numberList.add(99);


		// print to console - original List
		System.out.println("Orginal Integer List :- \n" + numberList + "\n");


		// 2.1 find particular number 93
		boolFind = numberList.contains(93);
		System.out.println("Number (93) present in List :- " + boolFind);


		// 2.2 find particular number 86
		boolFind = numberList.contains(86);
		System.out.println("Number (86) present in List :- " + boolFind);


		// 2.3 find particular number 55
		boolFind = numberList.contains(55);
		System.out.println("Number (55) present in List :- " + boolFind);


		// 2.4 find particular number 16
		boolFind = numberList.contains(16);
		System.out.print("Number (16) present in List :- " + boolFind);
	}
}

Output:

Orginal Integer List :- 
[97, 2, 19, 63, 23, 86, 55, 93, 21, 99]

Number (93) present in List :- true
Number (86) present in List :- true
Number (55) present in List :- true
Number (16) present in List :- false

2.2 Using Java 8 Stream :

  • Initially, there is a Integer List consisting of 10 integer numbers between 1 to 99
  • For finding particular number from a List or ArrayList using Java 8 Stream
    • Get Stream from List using list.stream() method
    • Then invoke anyMatch() method of Stream and check whether number exists in a List/ArrayList using equals() method by passing number to be find which will return result in the form of boolean either true/false
  • Finally, print the result to the console

FindNumberInListUsingJava8.java

package in.bench.resources.arrays.find.number;

import java.util.ArrayList;
import java.util.List;

public class FindNumberInListUsingJava8 {

	public static void main(String[] args) {

		// local variable
		Boolean boolFind = false;


		// 1. Integer List
		List<Integer> numberList = new ArrayList<Integer>();


		// 2. add numbers to List
		numberList.add(97);
		numberList.add(2);
		numberList.add(19);
		numberList.add(63);
		numberList.add(23);
		numberList.add(86);
		numberList.add(55);
		numberList.add(93);
		numberList.add(21);
		numberList.add(99);


		// print to console - original List
		System.out.println("Orginal Integer List :- \n" + numberList + "\n");


		// 2.1 find particular number 93
		boolFind = numberList.stream().anyMatch(number -> number.equals(93));
		System.out.println("Number (93) present in List :- " + boolFind);


		// 2.2 find particular number 86
		boolFind = numberList.stream().anyMatch(number -> number.equals(86));
		System.out.println("Number (86) present in List :- " + boolFind);


		// 2.3 find particular number 55
		boolFind = numberList.stream().anyMatch(number -> number.equals(55));
		System.out.println("Number (55) present in List :- " + boolFind);


		// 2.4 find particular number 16
		boolFind = numberList.stream().anyMatch(number -> number.equals(16));
		System.out.print("Number (16) present in List :- " + boolFind);
	}
}

Output:

Orginal Integer List :- 
[97, 2, 19, 63, 23, 86, 55, 93, 21, 99]

Number (93) present in List :- true
Number (86) present in List :- true
Number (55) present in List :- true
Number (16) present in List :- false

Related Articles :

References :

Happy Coding !!
Happy Learning !!

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