Java String valueOf()

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

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.