Week 2: String, Overflow and Type Casting

Overview

Welcome to your second week of learning C programming! This week, we will cover the basics of writing and running a simple C program. By the end of this tutorial, you will:

• Overflow, Underflow
• Handling String with
• Type Casting/Conversion

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** 1. Overflow **

You should always be careful of the range of values

Example: Overflow!

#include<stdio.h>
#define MAX 214783647
#define MIN -2147483648
int main(){

    printf("max value: %d\n",MAX);
    printf("min value: %d\n",MIN);

    printf("max +1 value: %d\n",MAX+1);
    printf("min -1 value: %d\n",MIN-1);

}

Exercise 1 (5 min):

Check the maximum and minimum values of other data types and see what happens when you go beyond the range of values —

2. String (15 min)

There are lots of functions in stirng.h that we can use when we deal with a string.

**Functions in **

Example: Using Variables

#include <stdio.h>
#include <string.h>
int main() {
    char hello[20]="hello";
    char world[20]="world";
    printf("%s%s\n",hello,world);
    strcat(hello,world);
    printf("%s and length of hello string is: %d\n",hello,strlen(hello));
    return 0;
}

Exercise 2 (10 min):

Create a program that introduce yourself by getting input of your last name, first name and age. *Please get input of your last, middle, first name seperately and print if by putting your name in one string variable.

Example: User Input

Hello, my name is JinseSeo and I am 24 years old. Nice to meet you!

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**3. Typecasintg **

You can converse data type

Example: User Input

#include<stdio.h>

int main(){

    int a=100;
    int b=3;
    float c=3.33;
    printf("%d and %f \n", a/b, (float)a/b);

    printf("%d and %f\n", (int)c, c);

    c=a/b;
    a=3.33;
    printf("%f and %d\n", c, a);
    return 0;
}

Exercise 3 (10 min):

Write a program that ask score of Math, English, Korean and print the average score to the second decimal place.

Example Output:

Your average score is 54.25

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Extra Exercise: Print Initials (5 min):

Write a program that asks the user to input their first and last name. The program should then print the initials in uppercase letters.

Example Input:

Taylor Adams

Example Output:

TA

**4. Assignment:

Inspired by previous assignments, let’s create a structured task:

Task: Write a C program that simulates a basic medical checkup. Your program should:

1. Ask the user for their last name, first name, age, gender (M/F), height (in cm) and weight (in kg).
2. Askt the user for their scores of Math, English, Korean and Art.
3. Print all this information using proper formatting.

BMI = Kg/m^2

Example Output:

You are JinseSeo, 24 years old and your gender is "M"
Your BMI is 21.749418
Your average score is 54.25

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Summary & Wrap-Up (10 min)

This week, we covered:

• Writing a simple C program
• Overflow, Underflow
• Utilizing String functions
• Type casting/conversion

Next Week: Basic C Programming - loops

Happy coding! 🚀