System.out.printf
- Java course
- Beginner
- Lesson 96/116
- 4 min
Learn formatted output with printf.
Formatted output with printf
System.out.printf produces tidy output using format placeholders. %s is for strings, %d for integers and %f for decimals. %n adds a platform-specific line break.
String name = "Ayşe";
int age = 30;
System.out.printf("Ad: %s, Yaş: %d%n", name, age);
// Ad: Ayşe, Yaş: 30printf slots values into a pattern instead of concatenating pieces one by one, so the output is more readable. Unlike println, printf does not add a line break automatically; you use %n for that.
Format a decimal number
%.2f shows a decimal with two digits after the point. %8.2f sets the total width to 8 and right-aligns it, which is handy for aligning tables neatly.
double price = 19.5;
System.out.printf("Fiyat: %.2f TL%n", price);
// Fiyat: 19.50 TL%.0f removes the fraction entirely and %,.2f adds grouping separators. This formatting is very useful for displaying money and statistics. printf does not change the value; it only formats how it appears.
Practice Format the price
Print the value double price = 19.5; using printf as Fiyat: 19.50 TL. Use two decimal digits and a line break.
Starter code
public class Main {
public static void main(String[] args) {
double price = 19.5;
// print with printf using two decimals and a line break
}
}Sample solution
System.out.printf("Fiyat: %.2f TL%n", price);Expected output
Fiyat: 19.50 TL
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match each placeholder to its type
| Term | Meaning |
|---|---|
%s |
String |
%d |
int |
%f |
double |
%n |
Line break |
2 Format with two digits
double price = 19.5;
System.out.printf("Fiyat: %____f TL%n", price);double price = 19.5;
System.out.printf("Fiyat: %.2f TL%n", price);Explanation: %.2f shows the decimal with two digits.
3 Which is a difference between println and printf?
- printf uses a pattern and placeholders, println does not Correct answer
- printf adds a line break automatically, println does not
- println only prints numbers, printf only prints strings
- they are exactly the same
Explanation: printf uses a format pattern and placeholders; println prints plain text as is.