Constants and literals - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of integer and floating-point constants

What is the output of this C program?

#include <stdio.h>
int main() {
    const int a = 5;
    const float b = 3.0f;
    printf("%d %.1f\n", a, b);
    return 0;
}

C

#include <stdio.h>
int main() {
    const int a = 5;
    const float b = 3.0f;
    printf("%d %.1f\n", a, b);
    return 0;
}

A 5 3.0

B 5 3

C 5.0 3.0

D 3 5.0

💡 Hint

Look at the format specifiers used in printf.

The integer constant 'a' is printed with %d showing 5, and the float constant 'b' is printed with %.1f showing 3.0.

❓ Predict Output

intermediate

Output of character and string literals

What will this C program print?

#include <stdio.h>
int main() {
    const char c = 'A';
    const char *s = "Hello";
    printf("%c %s\n", c, s);
    return 0;
}

C

#include <stdio.h>
int main() {
    const char c = 'A';
    const char *s = "Hello";
    printf("%c %s\n", c, s);
    return 0;
}

A Hello A

B 65 Hello

C A 'Hello'

D A Hello

💡 Hint

Remember that '%c' prints a single character and '%s' prints a string.

The character constant 'A' prints as 'A', and the string literal "Hello" prints as Hello.

❓ Predict Output

advanced

Output of octal and hexadecimal integer constants

What is the output of this C program?

#include <stdio.h>
int main() {
    int x = 010;  // octal 10
    int y = 0x10; // hex 10
    printf("%d %d\n", x, y);
    return 0;
}

C

#include <stdio.h>
int main() {
    int x = 010;  // octal 10
    int y = 0x10; // hex 10
    printf("%d %d\n", x, y);
    return 0;
}

A 8 16

B 10 10

C 16 8

D 010 0x10

💡 Hint

Octal 010 is 8 in decimal, hex 0x10 is 16 in decimal.

The octal constant 010 equals decimal 8, and the hexadecimal constant 0x10 equals decimal 16.

❓ Predict Output

advanced

Output of escape sequences in character constants

What does this C program print?

#include <stdio.h>
int main() {
    char c1 = '\n';
    char c2 = '\t';
    printf("%d %d\n", c1, c2);
    return 0;
}

C

#include <stdio.h>
int main() {
    char c1 = '\n';
    char c2 = '\t';
    printf("%d %d\n", c1, c2);
    return 0;
}

A 92 116

B 10 9

C n t

D 0 0

💡 Hint

Escape sequences represent special ASCII codes.

The newline '\n' is ASCII 10, and tab '\t' is ASCII 9.

❓ Predict Output

expert

Value of a floating-point constant with suffix

What is the output of this C program?

#include <stdio.h>
int main() {
    double d = 1.5;
    float f = 1.5f;
    printf("%.1f %.1f\n", d, f);
    return 0;
}

C

#include <stdio.h>
int main() {
    double d = 1.5;
    float f = 1.5f;
    printf("%.1f %.1f\n", d, f);
    return 0;
}

A 1.0 1.5

B 1.5 0.0

C 1.5 1.5

D 1.5 1.0

💡 Hint

The suffix 'f' makes the constant a float, but printing with %.1f shows the value.

Both variables hold the value 1.5; the suffix 'f' just sets the type to float.