Actually, as written, it does print the largest number, but only from sheer coincidence. The largest number in the array is 6, which is also the first number. Since the loop only runs once, it's already there.
However, let's talk about what you're likely really trying to do, and think about the best ways to do so.
Based on what you say, "to print out the largest number", a linear search need only find the largest number. It also doesn't need to find the position of that number in the array. So, let's figure out how to do that.
But first, let's cure a couple bad habits now. This program uses a global variable, which is ordinarily a very bad practice. A global variable is a variable that is declared outside of main or any function. In this case, A is a global variable. A global can be a very useful tool, but only when it makes sense to do so (as you'll learn later.)
Why is it a bad habit? It can lead to errors when the variable is reused or "shadowed" somewhere in the program where it shouldn't be. Global variable shadowing occurs when a global variable name is declared somewhere else in the code as a local variable. The local variable will be a completely separate variable and will mask or hide the global variable. This should be avoided at all costs. For example, suppose counter were declared as a global variable. Later, it's assigned a value of 12 in main. Then, it's redeclared in a function, where it is assigned a value of 15. When the function returns to main, the value of 12 remains in the global variable, and the local variable in the function is destroyed when processing exits the function.
Or, suppose in the same scenario, the programmer was depending on getting the global variable's value of 12, but accidently declared it in the function without assigning a value. It would initialize to 0 by default. You can see the problem.
So, never use a global variable if you don't absolutely have to!
Next, variable names should almost always be descriptive!
It's a bad practice to use single letter variable names! They should be descriptive of what they do, such as array_size instead of A. One of the very few exceptions is for use as a counter in a for loop. Even then, the loop should be fairly short (think a few dozen lines of code at most). When you have a large for or while loop, it's best to use descriptive names instead of single letters.
When using single letters in loops as counters, they should generally be i, j, k and so on, as it is traditional practice to use i for the outer loop and sequential letters for any nested loops inside that outer loop. Reusing i in subsequent outer loops is also standard practice. The important thing is to avoid confusion.
Now, on to the code to find the largest element in an array.
There are a lot of issues in the code above, too many to go through and be clear. So, since I don't believe this is actually an assignment, I decided to give you a clear example of how to accomplish it. Work through it yourself first to see if you understand. Pay special attention to what is being compared and how and where variables change.
#include <stdio.h>
void linear(int numbers[], int size);
int main(void)
{
int numbers[7] = {0, 4, 1, 6, 2, 3, 5};
// this is how you find the number of array elements
// divide the array total size by the size of the first element. Google it.
// note: you can't use this on a function parameter.
// See https://www.geeksforgeeks.org/using-sizof-operator-with-array-paratmeters-in-c/
int size = sizeof(numbers) / sizeof(numbers[0]) ;
linear(numbers, size);
}
void linear(int numbers[], int size)
{
int n = 0; // holds index of current largest value, starting at the first array element.
int i = 1; // a counter, starting at the second element in the array.
// find the index of the largest element
do
{
if (numbers[n] < numbers[i])
{
n = i;
}
i++;
} while (i < size);
printf("%i\n", numbers[n]);
}
Still, this code is problematic. What happens when there's only one element in the array? Will it fail? Will it produce a result? An error? Why don't you test that condition! ;-)
This would be better accomplished with a for loop than a while loop. (That's not to say there's not a better way to do it with a while loop.) Also, there are always multiple ways to do just about anything, but the most efficient (usually the simplest) is the best way.
The way to choose whether to use a for loop or a while or do/while loop is usually pretty straightforward.
If you have to do something until a certain test condition is met (such as A > B ) and you don't have a solid idea how many loop iterations it will take, then a while or do/while is probably the best choice.
If you have to do something a fixed number of times (meaning a fixed constant in the program or the number of times equal to the contents of a var ), then a for loop is usually the best choice. For example, if you have to look at every element in an array, for (int i = 0; i < array_count; i++) is the way to go. It consolidates the test and the counter incrementing into the for loop statement so you (or another programmer later) don't have to go searching for these control elements.
BTW, if you had only wanted to find the largest value, it would have been easier to just save the value in a var!
void linear(int numbers[], int size)
{
int n = 0; // holds index of current largest value, starting at the first array element.
int i = 1; // a counter, starting at the second element in the array.
// find the largest element
int largest = numbers[0];
// Note that this for loop will make sure
// that there's more than 1 element in the array.
for (int i = 1; i < size && size > 1; i++)
{
if (largest < numbers[i])
{
largest = numbers[i];
}
}
printf("%i\n", largest );
}
This code uses a for loop and also makes sure it doesn't fail when an array only has 1 element.
One more coding tip - always try to do things the simplest way possible! It avoids a lot of mistakes. If something feels too complicated, it probably is. Try to simplify it, or to try and do less at the same time in each code section.
Now, if you intended to actually sort the list, that's an entirely different discussion.
Questions? ;-)
If this answers your question, please click on the check mark to accept. Let's keep up on forum maintenance. ;-)
