Java 8 – How to convert primitive data-types into String ?

In this article, we will understand with a Java program on how to convert primitive data-types into String using Java 1.8 version

Already in one of the previous article, we discussed how to convert primitive data-types into String using earlier versions of Java like 5 or 7, etc.

Convert primitive data-types into String :

  • valueOf() method of String
    • This String method is used to return string representation of primitive data-types & Objects
  • There are 9 variants or overloaded valueOf() method, those are,

Method signature:

public static String valueOf(boolean b);
public static String valueOf(char c);
public static String valueOf(char[] data);
public static String valueOf(char[] data, int offset, int count);
public static String valueOf(int i);
public static String valueOf(long l);
public static String valueOf(float f);
public static String valueOf(double d);
public static String valueOf(Object obj);

ConvertPrimitiveIntoString.java

package in.bench.resources.java8.string.methods;

import java.util.stream.Stream;

public class ConvertPrimitiveIntoString {

	public static void main(String[] args) {

		// 1. boolean variables
		boolean boolTest1 = false, 
				boolTest2 = true;


		// 1.1 convert boolean to String
		String boolToStr1 = Stream.of(boolTest1).map(String::valueOf).findAny().get();
		System.out.println("boolean (false) converted to String = " + boolToStr1);


		// 1.2 convert boolean to String
		String boolToStr2 = Stream.of(boolTest2).map(String::valueOf).findAny().get();
		System.out.println("boolean (true) converted to String = " + boolToStr2);



		// 2. char variables
		char charTest1 = 'z', 
				charTest2 = 'N';


		// 2.1 convert char to String
		String charToStr1 = Stream.of(charTest1).map(String::valueOf).findAny().get();
		System.out.println("\nchar 'z' converted to String = " + charToStr1);


		// 2.2 convert char to String
		String charToStr2 = Stream.of(charTest2).map(String::valueOf).findAny().get();
		System.out.println("char 'N' converted to String = " + charToStr2);



		// 3. char[] Arrays variables
		char[] charArrTest1 = {'B', 'e', 'n', 'c', 'h'}, 
				charArrTest2 = {'F', 'r', 'i', 'e', 'n', 'd'};


		// 3.1 convert char[] Arrays to String
		String charArrToStr1 = Stream.of(charArrTest1).map(String::valueOf).findAny().get();
		System.out.println("\nchar[] Arrays {'B', 'e', 'n', 'c', 'h'} converted to String = " 
				+ charArrToStr1);


		// 3.2 convert char[] Arrays to String
		String charArrToStr2 = Stream.of(charArrTest2).map(String::valueOf).findAny().get();
		System.out.println("char[] Arrays {'F', 'r', 'i', 'e', 'n', 'd'} converted to String = " 
				+ charArrToStr2);



		// 4. double variables
		double dblTest1 = 19.23456, 
				dblTest2 = 258.589635;


		// 4.1 convert double to String
		String dblToStr1 = Stream.of(dblTest1).map(String::valueOf).findAny().get();
		System.out.println("\ndouble (19.23456) converted to String = " + dblToStr1);


		// 4.2 convert double to String
		String dblToStr2 = Stream.of(dblTest2).map(String::valueOf).findAny().get();
		System.out.println("double (258.589635) converted to String = " + dblToStr2);



		// 5. float variables
		float fltTest1 = 29.23456f, 
				fltTest2 = 158.589635f;


		// 4.1 convert float to String
		String fltToStr1 = Stream.of(fltTest1).map(String::valueOf).findAny().get();
		System.out.println("\nfloat (29.23456f) converted to String = " + fltToStr1);


		// 4.2 convert float to String
		String fltToStr2 = Stream.of(fltTest2).map(String::valueOf).findAny().get();
		System.out.println("float (158.589635f) converted to String = " + fltToStr2);



		// 6. int variables
		int intTest1 = 63, 
				intTest2 = 97;


		// 6.1 convert int to String
		String intToStr1 = Stream.of(intTest1).map(String::valueOf).findAny().get();
		System.out.println("\ninteger (63) converted to String = " + intToStr1);


		// 6.2 convert int to String
		String intToStr2 = Stream.of(intTest2).map(String::valueOf).findAny().get();
		System.out.println("integer (97) converted to String = " + intToStr2);



		// 7. long variables
		long longTest1 = 1912345, 
				longTest2 = 333444999;


		// 7.1 convert long to String
		String longToStr1 = Stream.of(longTest1).map(String::valueOf).findAny().get();
		System.out.println("\nlong (1912345) converted to String = " + longToStr1);


		// 7.2 convert long to String
		String longToStr2 = Stream.of(longTest2).map(String::valueOf).findAny().get();
		System.out.println("long (333444999) converted to String = " + longToStr2);
	}
}

Output:

boolean (false) converted to String = false
boolean (true) converted to String = true

char 'z' converted to String = z
char 'N' converted to String = N

char[] Arrays {'B', 'e', 'n', 'c', 'h'} converted to String = Bench
char[] Arrays {'F', 'r', 'i', 'e', 'n', 'd'} converted to String = Friend

double (19.23456) converted to String = 19.23456
double (258.589635) converted to String = 258.589635

float (29.23456f) converted to String = 29.23456
float (158.589635f) converted to String = 158.58963

integer (63) converted to String = 63
integer (97) converted to String = 97

long (1912345) converted to String = 1912345
long (333444999) converted to String = 333444999

Q) Difference between int and long ?

  • primitive int (integer) data-type is 32-bit
  • primitive long data-type is 64-bit

Q) Difference between float and double ?

  • Both are used to represent floating numbers where,
    • primitive float data-type is 32-bit and always followed with suffix ‘f
    • primitive double data-type is 64-bit

Related Articles:

References:

Happy Coding !!
Happy Learning !!

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