Output formatting basics in Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this formatted print statement?

Consider the following Java code snippet. What will it print to the console?

Java

System.out.printf("Name: %s, Age: %d\n", "Alice", 30);

A Name: Alice, Age: 30

B Name: Alice Age: 30

C Name: %s, Age: %d

D Name: Alice, Age: %d

💡 Hint

Look at how %s and %d are replaced by the values in order.

The printf method replaces %s with the string "Alice" and %d with the integer 30, printing them formatted.

❓ Predict Output

intermediate

What does this code print with width formatting?

What is the output of this Java code?

Java

System.out.printf("|%10s|%5d|\n", "Bob", 7);

A |Bob |7 |

B | Bob| 7|

C |Bob|7|

D | Bob| 7|

💡 Hint

The number after % indicates minimum width, right aligned by default.

The string "Bob" is printed right aligned in a field 10 characters wide, and 7 is printed right aligned in 5 spaces.

❓ Predict Output

advanced

What is the output with floating-point precision formatting?

What does this Java code print?

Java

System.out.printf("%.2f\n", 3.14159);

A 3.14159

B 3.1

C 3.15

D 3.14

💡 Hint

%.2f means print a floating number with 2 digits after decimal.

The number 3.14159 is rounded to two decimal places, printing 3.14.

❓ Predict Output

advanced

What is the output of this left-aligned formatted print?

What will this Java code print?

Java

System.out.printf("|%-10s|%5d|\n", "Cat", 42);

A |Cat|42|

B | Cat| 42|

C |Cat | 42|

D |Cat |42 |

💡 Hint

%-10s means left-align the string in 10 spaces.

The string "Cat" is printed left aligned in 10 spaces, and 42 is right aligned in 5 spaces.

❓ Predict Output

expert

What is the output of this complex formatted print?

What does this Java code print?

Java

System.out.printf("%-8s %04d %.3f\n", "Dog", 7, 2.71828);

A Dog 0007 2.718

B Dog 7 2.718

C Dog 7 2.718

D Dog 0007 2.72

💡 Hint

%-8s left aligns string in 8 spaces, %04d pads integer with zeros to 4 digits, %.3f prints float with 3 decimals.

The string "Dog" is left aligned in 8 spaces, 7 is padded with zeros to 0007, and 2.71828 is rounded to 2.718.