Java Convert int to String

In Java, converting an integer (int) to a string is a common operation essential for data processing and output formatting. This article explores "int to string Java" conversion methods, highlighting efficient techniques and best practices to integrate numeric data into textual contexts seamlessly.

How to Convert int to String in Java?

Using the toString() Method of the Integer Class

The toString() method of the Integer class expresses an integer value as a string. It takes an integer value as an argument and returns the string representation of the argument value.

Syntax:

Example Java Program:

Output:

Explanation:

• The integer variables and values were converted into string types using the Integer.toString(int_var) function, and the resultant value was then assigned to the String objects. We have printed the values of the integer and String objects as the last step.

Using the valueOf() Method of the String Class

valueOf() is a static method that is overloaded within the String class for all the Java primitive types. valueOf() method takes one argument, i.e., the integer variable or an integer value, and returns the string representation of that integer value.

Syntax:

Example Java Program:

Output:

Explanation:

• In the above Java program, we initialize an integer a = 39 and directly use 49 for conversion. By employing String.valueOf(), we convert these integers to strings, assigning the results to str_a and str_b. The values of a, str_a, and str_b are then printed, showcasing the conversion.

Using Integer(int).toString() Method of Integer Class

To use the Integer(int_var).toString() technique to convert the argument integer value to the String type, we first need to create an instance of the Integer class.

Syntax:

or

Example Java Program:

Output:

Explanation:

• In the above Java program, we initialize an integer a = 7007 and also use the literal 39 for conversion. The results are stored in String variables and displayed, showcasing the conversion of the Integer object obj and the strings str_a and str_b.

Using Concatenation with an Empty String

The DecimalFormat class of the java.text package in Java is used to format integer values using a custom formatting pattern. The DecimalFormat class can format various sorts of numbers by converting the numeric values to String class objects.

Syntax:

Example Java Program:

Output:

Explanation:

• In the above Java program, we initialize two integers, a = 4500 and b = 4350, and also use a direct value of 910000 for string conversion. The output demonstrates that a converts to str_a = 4500 without commas, whereas b and 910000 are formatted to str_b = 4,350 and str_c = 910,000, incorporating commas for every three digits from the right. The resulting string values str_a, str_b, and str_c are then displayed.

Advanced Methods to Convert int to String in Java

Using DecimalFormat Class

Syntax:

Code:

Output:

Explanation: The DecimalFormat class is used for formatting numbers in a locale-sensitive manner. In this example, the #,### pattern is used to format the integer, adding a comma as a thousand separator, converting the int to a formatted String.

Using StringBuffer Class

Syntax:

Code:

Output:

Explanation: The StringBuffer class creates a mutable sequence of characters. The append method converts the integer to a StringBuffer instance, and the toString method converts it into a String.

Using StringBuilder Class

Syntax:

Code:

Output:

Explanation: Similar to StringBuffer, the StringBuilder class is used for creating a mutable sequence of characters. The difference lies in synchronization; StringBuilder is faster as it's not synchronized.

Using Special Radix and Custom Radix

Syntax:

Code (Special Radix - Binary):

Output (Binary):

Code (Custom Radix - Hexadecimal):

Output (Hexadecimal):

Explanation: Java provides the ability to convert integers to strings with different radix values, enabling binary, hexadecimal, and other base conversions. The Integer.toString method uses the desired radix, allowing for flexible string representations of numeric values.