Methods to Convert Integer to String in Java
In this article, we will learn different methods to convert an integer to a string with the help of examples.
In this article, we will learn how to convert an integer to a string in Java, where integers and strings are different data types in Java. This article will briefly discuss different methods to convert integers to strings.
So, before moving further let’s discuss what is int data types in java?
int is a primitive data type in java used to declare a variable in the program. Some points to remember about int are:
- The default value of int is 0
- The default size of int is 4 bytes
- The range of int is from – 231 to 231
int is declared in Java as:
int a = 100;
Note: Don’t be confused with int and Integer in Java since, int is a non-primitive data type in java, whereas Integer is wrapper class in Java.
Why do we need to convert int to String?
In the programming world, we come across various scenarios where we have to perform operations which we do easily with String as compared to an integer because of various inbuilt methods present in String. When it comes to integers, inbuilt methods are a little.
Suppose we want to concatenate two integers, then it is a complex task, then do the same thing with String. We have to dig into the number system, do mathematics, and make functions to accomplish the concatenation of integers. Still, with String, we have to use the concate() method or the “+” operator for the same task. So, that’s why we convert integers into String to accomplish such problems that we face while writing programs or algorithms.
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Methods to Convert an Integer to a String
- Integer.toString()
- String.valueOf()
- String.format()
- Concatenation with Empty String
- StringBuffer class
- StringBuilder class
- DecimalFormat class
- String() method of the Integer class
By using Integer.toString()
Let’s see the below program in which we convert an integer into a String by using Integer.toString() method.
Program:
public class Main{ public static void main(String args[]) { // create an integer variable a and assign 100 value to it int a=100; //Convert integer a to String by using Integer.toString() method String hundred=Integer.toString(a); //Print String variable hundred System.out.println(hundred); }}
Output:
By using String.valueOf()
Let’s see the below program in which we convert an integer into a String by using String.valueOf() method.
Program:
public class Main{ public static void main(String args[]) { // create an integer variable a and assign 100 value to it int a=100; //Convert integer a to String by using String.valueOf() method String hundred=String.valueOf(a); //Print String variable hundred System.out.println(hundred); }}
Output:
By using String.format()
Let’s see the below program in which we convert an integer into a String by using String.format() method.
Program:
public class Main{ public static void main(String args[]) { // create a integer variable a and assign 100 value to it int a=100; //Convert integer a to String by using String.format() method String hundred=String.format("%d",a); //Print String variable hundred System.out.println(hundred); }}
Output:
By using Concatenation with Empty String
In the below program, we create an empty String and merge the integer with the “+” operator and store the resultant as String.
Program:
public class Main{ public static void main(String args[]) { // create a integer variable a and assign 10 value to it int a=10; //Creating an empty String String empty_string=""; //merge integer with empty String String ten=empty_string+10; //printing String ten System.out.println(ten); }}
Output
By using the StringBuffer class
In the below program, we first add an integer value to the StringBuffer object and then convert that value into a String using the toSrting() method of the StringBuffer class.
Program:
public class Main{ public static void main(String args[]) { // create a integer variable a and assign 10 value to it int a=10; //Creating object of StringBuffer class StringBuffer sb=new StringBuffer(); // append() function add or append the value to StringBuffer object sb.append(a); //value contained inside StringBuffer is convert into String String ten=sb.toString(); //print String ten System.out.println(ten); }}
Output:
By using the StringBuilder class
In the below program, we first add an integer value to the StringBuilder object and then convert that value into a String using the toSrting() method of the StringBuilder class.
Program:
public class Main{ public static void main(String args[]) { // create a integer variable a and assign 10 value to it int a=10; //Creating object of StringBuilder class StringBuilder sb=new StringBuilder(); // append() function add or append the value to StringBuilder object sb.append(a); //value contained inside StringBuilder is convert into String String ten=sb.toString(); // printing String ten System.out.println(ten); }}
Output:
By using DecimalFormat class
In the below program, we use the DecimalFormat class and call format() method to convert integer into String.
Program:
//Import required classimport java.text.DecimalFormat;
public class Main{ public static void main(String args[]) { // create a integer variable a and assign 10 value to it int a=10; //creating object of DecimalFormat class DecimalFormat df=new DecimalFormat(); //converting integer a into String using format method and store it in String ten String ten=df.format(a); //printing String ten System.out.println(ten); }}
public class Main{ public static void main(String args[]) { // create a integer variable a and assign 10 value to it int a=10; //creating object of Integer Integer obj=new Integer(a); //converting integer into String using toString() method of Integer class String ten=obj.toString(); //printing String ten System.out.println(ten); }}
Output:
Conclusion
In this article, we have discussed different methods to convert an integer to a string with the help of examples.
Hope you will like the article.
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Contributed By: Shubham Kumar
This is a collection of insightful articles from domain experts in the fields of Cloud Computing, DevOps, AWS, Data Science, Machine Learning, AI, and Natural Language Processing. The range of topics caters to upski... Read Full Bio
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