How do you write a C language program that will compare and return the biggest number between variables?

Answer 1

To return the largest of a set of variables, store the first variable's value and compare it with all the others, one after the other. Each time a larger value is found, update the stored value. When all variables have been compared, the stored value holds the largest value.

The following demonstrates how to do this for an array of integers:

int largest (int* arr, unsigned size) {

if (!arr size==0) return INT_MIN; // check for invalid arguments

int store = arr[0]; // store first element

for (unsigned i=1; i<size; ++i) if (arr[i]>store) store = arr[i]; // compare with all other values

return store;

}