Multiple input and output in C - Mini Project: Build & Apply

Multiple input and output

📖 Scenario: You are creating a simple program to record the names and ages of three friends. You will input their names and ages, then display this information clearly.

🎯 Goal: Build a C program that takes the names and ages of three friends as input and then prints each friend's name with their age.

📋 What You'll Learn

Use arrays to store names and ages

Use a loop to input data for three friends

Use a loop to output the stored data

Use scanf and printf for input and output

💡 Why This Matters

🌍 Real World

This kind of program helps in collecting and displaying simple records like names and ages, useful in small databases or contact lists.

💼 Career

Understanding multiple inputs and outputs is essential for many programming tasks such as data entry, processing user information, and building interactive applications.

1

Create arrays for names and ages

Declare a 2D character array called names with size 3 by 20 to store three names, and an integer array called ages with size 3 to store their ages.

C

# Declare arrays for names and ages
# Your code here

Need a hint?

Use char names[3][20]; to store three names each up to 19 characters plus null terminator.

2

Add a loop to input names and ages

Add a for loop with variable i from 0 to less than 3. Inside the loop, use scanf("%19s", names[i]) to input each name and scanf("%d", &ages[i]) to input each age.

C

#include 

char names[3][20];
int ages[3];

int main() {
    // Input names and ages
    // Your code here
    return 0;
}

Need a hint?

Use a for loop to input data for each friend.

3

Add a loop to output names and ages

Add a for loop with variable i from 0 to less than 3. Inside the loop, use printf("%s is %d years old\n", names[i], ages[i]) to print each friend's name and age.

C

#include 

char names[3][20];
int ages[3];

int main() {
    for (int i = 0; i < 3; i++) {
        scanf("%19s", names[i]);
        scanf("%d", &ages[i]);
    }
    // Output names and ages
    // Your code here
    return 0;
}

Need a hint?

Use a for loop to print each friend's information.

4

Print the final output

Run the program and input these three friends' data exactly in this order:
Alice 25
Bob 30
Charlie 22
Then print the output exactly as:
Alice is 25 years old
Bob is 30 years old
Charlie is 22 years old

C

#include 

char names[3][20];
int ages[3];

int main() {
    for (int i = 0; i < 3; i++) {
        scanf("%19s", names[i]);
        scanf("%d", &ages[i]);
    }
    for (int i = 0; i < 3; i++) {
        printf("%s is %d years old\n", names[i], ages[i]);
    }
    // Run and check output
    // Your code here
    return 0;
}

Need a hint?

Type the names and ages exactly as shown, then check the printed output.