String Formatting

What is String Formatting?

We format strings in Java for clarity, control, and consistency. It enhances code readability, allows us to precisely present data (numbers, dates, etc.), and ensures consistent output across the application. This improves maintainability, user experience, and sometimes even efficiency.

String Specifiers

We use specifiers to be a placeholder of where a data should be placed in a String.

Specifier	Explanation
%s	Converts the data attached automatically to a String equivalent data
%d	Used for Integers, allows the placement of integers within a string
%f	Used for decimals/floats/doubles. This allows decimal values to be represented in a string. You can also control the decimal place.

Formatting a string

String name = "Alice";
String greeting = String.format("Hello, %s!", name);
System.out.println(greeting); // Output: Hello, Alice!

Formatting numbers:

int age = 30;
String message = String.format("My age is %d.", age);
System.out.println(message); // Output: My age is 30.

Formatting numbers with decimals:

double price = 123.456789;
String formattedPrice = String.format("%.2f", price);
System.out.println(formattedPrice); // Output: 123.46

Using multiple arguments:

String firstName = "Bob";
String lastName = "Smith";
String fullName = String.format("%s %s", firstName, lastName);
System.out.println(fullName); // Output: Bob Smith