How to fix "assigned a value that is never used " error?

[dkyadav80]

" "a" is assigned a value that is never used " getting error in C programming.

pls any one solve this question. when and why becomes this type problem in turbo C/C++ compiler
char a;
FILE *f1;
while((a=getc(f 1))!='\n')//

[horace1]

you define a

char a;

but don't give it a value - so when it is used in the expresion

while((a=getc(f1))!='\n')//

you get a result which depends upon the value that happened to be in the memory assigned to a

[Banfa]

The error is indicating that while you are assigning a value to a in your while loop a is then never used so the assignment serves no purpose.

Effectively you code

char a;
FILE *f1;
while((a=getc(f1))!='\n')//

could, without effecting the operation of the rest of your program, be replaced with

FILE *f1;
while(getc(f1)!='\n')//

[donbock]

You called this an error; but "assigned a value that is not used" is more typically a warning. A warning is a message from the compiler that your program is not doing anything illegal, but it is doing something odd.