How to write the temperature conversion table by using function?

Temperature conversion is nothing but converting Fahrenheit temperature to Celsius or Celsius to Fahrenheit. In this programming, we are going to explain how to convert the Fahrenheit temperature to Celsius temperature and how to represent the same in the form of a table by using a function.

Syntax

// Function to convert Fahrenheit to Celsius
float fahrenheitToCelsius(float fahrenheit);

// Function to convert Celsius to Fahrenheit  
float celsiusToFahrenheit(float celsius);

Example 1: Fahrenheit to Celsius Conversion Table

Following is the C program for temperature conversion table from Fahrenheit to Celsius −

#include <stdio.h>

float fahrenheitToCelsius(float fh) {
    float cl;
    cl = (fh - 32) * 5 / 9;
    return cl;
}

int main() {
    float fh, cl;
    int begin = 0, stop = 300;
    
    printf("Fahrenheit \t Celsius<br>");
    printf("----------\t-----------<br>");
    
    fh = begin;
    while (fh <= stop) {
        cl = fahrenheitToCelsius(fh);
        printf("%3.0f\t\t%6.1f<br>", fh, cl);
        fh = fh + 20;
    }
    return 0;
}

Fahrenheit 	 Celsius
----------	-----------
  0		 -17.8
 20		  -6.7
 40		   4.4
 60		  15.6
 80		  26.7
100		  37.8
120		  48.9
140		  60.0
160		  71.1
180		  82.2
200		  93.3
220		 104.4
240		 115.6
260		 126.7
280		 137.8
300		 148.9

Example 2: Celsius to Fahrenheit Conversion Table

Here is the program for converting Celsius to Fahrenheit using a function −

#include <stdio.h>

float celsiusToFahrenheit(float cl) {
    float fh;
    fh = (cl * 9 / 5) + 32;
    return fh;
}

int main() {
    float cl, fh;
    int begin = 0, stop = 150;
    
    printf("Celsius \t Fahrenheit<br>");
    printf("-------\t\t-----------<br>");
    
    cl = begin;
    while (cl <= stop) {
        fh = celsiusToFahrenheit(cl);
        printf("%3.0f\t\t%6.1f<br>", cl, fh);
        cl = cl + 10;
    }
    return 0;
}

Celsius 	 Fahrenheit
-------		-----------
  0		  32.0
 10		  50.0
 20		  68.0
 30		  86.0
 40		 104.0
 50		 122.0
 60		 140.0
 70		 158.0
 80		 176.0
 90		 194.0
100		 212.0
110		 230.0
120		 248.0
130		 266.0
140		 284.0
150		 302.0

Key Points

• The conversion formulas are: Celsius = (Fahrenheit - 32) × 5/9 and Fahrenheit = (Celsius × 9/5) + 32
• Using functions makes the code modular and reusable for different temperature ranges
• The while loop generates the table by incrementing temperature values

Conclusion

Temperature conversion tables can be efficiently created using functions in C. This approach provides clean, readable code and allows easy modification of temperature ranges and increment values.