![I'm trying to make a program to switch letter cases, from lower case to upper case and vice versus, but I can't get it to run through the first if statement, any I'm trying to make a program to switch letter cases, from lower case to upper case and vice versus, but I can't get it to run through the first if statement, any](https://preview.redd.it/aad3t99ao4n11.jpg?auto=webp&s=085cbf61e399d68155bb84f5882b73723195830a)
I'm trying to make a program to switch letter cases, from lower case to upper case and vice versus, but I can't get it to run through the first if statement, any
![Use the function toupper() in combination with the .strstr() function to find out whether one string occurs in another, ignoring case. - C String Use the function toupper() in combination with the .strstr() function to find out whether one string occurs in another, ignoring case. - C String](http://www.java2s.com/example/c/string/use-the-function-toupper-in-combination-with-the-.strstr-function--e4fb8.png)
Use the function toupper() in combination with the .strstr() function to find out whether one string occurs in another, ignoring case. - C String
![C Program to convert character(s) to uppercase using the toupper() Function | C Programs | Studytonight C Program to convert character(s) to uppercase using the toupper() Function | C Programs | Studytonight](https://static.studytonight.com/c/programs/output/toupper()-function.png)