What happens when a variable is not initialized in main function?

When a variable is not initialized in main function it contains garbage value. This can be well seen from the example below

main() { int x; printf(“%d”,x); z= sample() }

sample() { printf(“Testing program”); }

Output is

    x=80

Testing program

The above program prints a garbage value and the output testing program. This is because the variable x is not initialized and so the variable x had garbage value which is printed first then the function sample is called which gave output as testing program. Thus it is essential to initialize variables in main () function.