Last Updated on 2021-04-29 by Clay
In the previous note, I recorded how to program conversion between Celsius and Fahrenheit ([C] Variables and Arithmetic Expressions). In the process, we continuously increase the Fahrenheit temperature through the while
loop, and view the converted Celsius temperature result.
If you want the program to execute the same command over and over again, you can also use a for
loop to do this.
For loop
We rewrite the Celsius and Fahrenheit temperature conversion program from the previous note:
#include <stdio.h> int main() { float F, C; int lower = 0; int upper = 300; int step = 20; // For-loop for (F=0; F<=300; F+=step) { C = (5.0 / 9.0) * (F - 32.0); printf("%3.0f %6.1f\n", F, C); } return 0; }
Output:
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
It can be seen that using for
loop and while
loop can achieve the same effect.
The settings in the for
loop are divided into three conditions:
for(INITIAL_VALUE; EXECUTE_CONDITION; UPDATE_VALUE)
INITIAL_VALUE is a initial condition when the for
loop starts to execute, here is the case of F=0.
The EXECUTION_CONDITION is F<=300, which means that the loop will be executed until F exceeds 300.
The UPDATE_VALUE is F+=step (F+=20), that is, the value of F is fixedly updated at the end of each loop. If you don't do this, the loop will run forever.
References
- https://www.programiz.com/c-programming/c-for-loop
- https://www.tutorialspoint.com/cprogramming/c_for_loop.htm