NumberFormat and printf
Format numbers for display using NumberFormat, DecimalFormat, and printf patterns.
NumberFormat and printf
Java provides rich number formatting APIs: NumberFormat for locale-aware currency/percent, DecimalFormat for custom patterns, and printf/String.format for C-style formatting.
String.format Basics
String.format() uses format specifiers to build strings. Common specifiers: %d (integer), %f (float), %s (string), %n (newline).
String name = "Alice";
int score = 95;
double avg = 87.567;
String msg = String.format(
"Player: %s | Score: %d | Average: %.2f", name, score, avg);
System.out.println(msg);
// Player: Alice | Score: 95 | Average: 87.57
// printf is equivalent — formats directly to output
System.out.printf("%-10s %5d %8.2f%n", name, score, avg);
// Alice 95 87.57All lessons in this course
- The Math Class Essentials
- Integer Arithmetic & Overflow
- BigDecimal for Financial Calculations
- NumberFormat and printf