Formatting of Strings in Java

ゝ一纸荒年。 2023-01-19 03:09 6阅读 0赞

## Introduction ##

In Java, we can format strings depending on our needs and get the required output. The printf command is very useful in Java. The printf command takes text as a string and formats it depending on the instructions given to it.

## String Formatting ##

*  **"%s"** Format a string with the required number of characters.
 *  **"%10s"** Format a string with the specified number of characters and also right justify.
 *  **"%-10s"** Format a string with the specified number of characters and also left justify.

For formatting numbers, we use the "d" character and for floating-point numbers we use the "f" character.

**Example**

1.      package demo;  
        public class Demo {  
         public static void main(String args[]) {  
          String n = "NAME";  
          System.out.printf("%10s %n", n);  
         }  
        }

**Output**

![string formatting right justify][]

**Example**

1.      package demo;  
        public class Demo {  
         public static void main(String args[]) {  
          String n = "NAME";  
          String l = "LOCATION";  
          System.out.printf("%-10s %10s %n", n, l);  
         }  
        }

**Output**

![string formatting left justify][]

### **Integer Formatting** ###

*  **"%d" **Format a string with the required numbers.
 *  **"%5d"** Format a string with the required number of integers and also pad with spaces to the left side if integers are not adequate.
 *  **"%05d"** Format a string with the required number of integers and also pad with zeroes to the left if integers are not adequate.

**Example**

1.      package demo;  
        public class Demo {  
         public static void main(String args[]) {  
          String r = "ROLL NO";  
          int i = 12345;  
          System.out.printf("%s %15d %n", r, i);  
         }  
        }

**Output**

![integer formatting][]

**Example**

1.      package demo;  
        public class Demo {  
         public static void main(String args[]) {  
          int r = 54321;  
          int i = 12345;  
          System.out.printf("%015d %15d %n", r, i);  
         }  
        }

**Output**

![integer formatting with zeroes][]

### Floating Point Number Formatting ###

*  **"%f"** Format a string with the required numbers. It will always give six decimal places.
 *  **"%.3f"** Format a string with the required numbers. It gives three decimal places.
 *  **"%12.3f"** Format a string with the required numbers. The string occupies twelve characters. If numbers are not adequate then spaces are used on the left side of the numbers.

**Example**

1.      package demo;  
        public class Demo {  
         public static void main(String args[]) {  
          System.out.printf("%.3f %n", 123.45789);  
         }  
        }

**Output**

![floating point no. formatting][]

**Example**

1.      package demo;  
        public class Demo {  
         public static void main(String args[]) {  
          System.out.printf("%12.3f %n", 123.45789);  
         }  
        }

**Output**

![floating point no. formatting with spaces][]

## Summary ##

This article explains string formatting in Java and the use of the printf command in Java.

reference：[https://www.c-sharpcorner.com/UploadFile/3614a6/formatting-of-strings-in-java/][https_www.c-sharpcorner.com_UploadFile_3614a6_formatting-of-strings-in-java]

[string formatting right justify]: /images/20221021/697a70ba4e634972a4661a67459c3f0c.png
[string formatting left justify]: /images/20221021/1fcfe8beb6f5403a96c03f5561c15696.png
[integer formatting]: /images/20221021/49b56d4e69df4647bdeb8aad357f88fc.png
[integer formatting with zeroes]: /images/20221021/818edd1cf4834276abc4c21fb12af9c1.png
[floating point no. formatting]: /images/20221021/5fc196e1906d45438a313fa6ec5e2b03.png
[floating point no. formatting with spaces]: /images/20221021/d5a73a3d2e6b41a0915e6eae3217f3b1.png
[https_www.c-sharpcorner.com_UploadFile_3614a6_formatting-of-strings-in-java]: https://www.c-sharpcorner.com/UploadFile/3614a6/formatting-of-strings-in-java/