Java String valueOf()

In this tutorial, we will learn about the Java String valueOf() method with the help of examples.

The valueOf() method returns the string representation of the argument passed.

Example

class Main {
  public static void main(String[] args) {

    double interest = 923.234d;

// convert double to string System.out.println(String.valueOf(interest));
} } // Output: 923.234

Syntax of valueOf()

The syntax of the String valueOf() method for different data types is:

String.valueOf(boolean b)
String.valueOf(char c)
String.valueOf(char[] data)
String.valueOf(double d)
String.valueOf(float f)
String.valueOf(int b)
String.valueOf(long l)
String.valueOf(Object o)

Here, valueOf() is a static method. We call the valueof() method using the class name like this: String.valueOf(b);


valueOf() Parameters

The valueOf() method takes a single parameter.

  • data that is to be converted to a string

valueOf() Return Value

  • returns the string representation of the argument passed

Example: Java String valueOf() for Numbers

class Main {
  public static void main(String[] args) {
    int a = 5;
    long l = -2343834L;
    float f = 23.4f;
    double d = 923.234d;

    // convert numbers to strings
    System.out.println(String.valueOf(a));  // "5"
System.out.println(String.valueOf(l)); // "-2343834" System.out.println(String.valueOf(f)); // "23.4"
System.out.println(String.valueOf(d)); // "923.234" } }

Example 2: Convert char and char array to String

In Java, you can also use the + operator to concatenate two strings. For example,

class Main {
  public static void main(String[] args) {
    char c = 'J';
    char ch[] = {'J', 'a', 'v', 'a'};

    // convert char to string
System.out.println(String.valueOf(c)); // "J"
// convert char array to string
System.out.println(String.valueOf(ch)); // "Java"
} }

Convert subarray of the char Array to String

You can also convert a subarray of a character array to string. For this, we use this syntax.

valueOf(char[] data, int offset, int length)

Here,

  • data - the character array
  • offset - initial offset of the subarray
  • count - the length of the subarray

Example 3: Subarray of a char Array to String

class Main {
  public static void main(String[] args) {
    char ch[] = {'p', 'r', 'o', 'g', 'r', 'a', 'm'};
    int offset = 2;
    int length = 4;
    String result;

// subarray {'o', 'g', 'r', 'm'} is converted to string result = String.valueOf(ch, offset, length);
System.out.println(result); // "ogrm" } }

Example 4: Convert Object to String

import java.util.ArrayList;

class Main {
  public static void main(String[] args) {

    ArrayList<String> languages = new ArrayList<String>();
    languages.add("Java");
    languages.add("Python");
    languages.add("Kotlin");

    String result;

// Output: "[Java, Python, Kotlin]" result = String.valueOf(languages);
System.out.println(result); } }

Here, an ArrayList object, languages, is converted to a string.


In Java, there is another method named copyValueOf() which is equivalent to the valueOf() method.

Note: You can also use the object.toString() method to convert an object to a string. To learn more, visit: Java Object toString() method.

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