Thread: An if statement that checks all the elements of an array

I have been trying to find a general method to typing the following code.

if ( colb[1][mb] == '*' && colb[2][mb] == '*' && colb[3][mb] == '*' && colb[x][mb] == '*' )

This is ok but by about x = 10 its just too painful.
I have thought of a solution whereby you make a for loop outside that basically breaks if (and return 0 to some int- check_colb) any of the cob[n][mb] != '*'
and the if loop can just check if check_colb is 1 or 0.

However I am wonder is there a specific syntax or method that is typical in such situations? (I am thinking there must be...)

This is the first time I am in the computer science forum, nice to meet you all.

Some languages have an "one of" or "all" type command, where you supply a test function and it returns whether that applies to one of, or all, the elements of a collection. Not all languages support this though, but I think Java and C++ both have something like this in their standard libraries (at least, with the new C++ standard).

BTW, your loop is basically the standard way of doing it, and basically what any library call would end up doing anyway.

Sorry, I didn't specify the language....

Does C have this function by any chance? I guess I can easily make it.

Originally Posted by tikai

Sorry, I didn't specify the language....

Does C have this function by any chance? I guess I can easily make it.

Well, as far as I know there aren't any. But never mind those, the general method is small and efficient enough so you won't need any libraries. But, if you still want some then I suggest you make a library yourself and add all the functions that you commonly use. In fact, that's what all big programmers do.

The STL is one of several reasons I prefer C++ over C.

As far as I know it would be impossible to do this in a generic way in C, since each type would need its own function, so I wouldn't expect to find this in any of the standard headers.

Code:

{
    int result = 1;
    int i;

    ...

    for ( i = 1; i <= x && result; i++ )
    {
        result &&= colb[i][mb] == '*';
    }
    
    if ( result )
    {
        /* whatever you want */
    }
}

This also imitates laziness of &&.

If you are coding in C you may also use goto:

Code:

    for ( i = 1; i <= x; i++ )
    {
        if ( colb[i][mb] != '*' )
        {
            goto avoid;
        }
    }

    /* if true */

    avoid:

C is a pretty old programming language. It was created in early seventies. So it has no modern syntax constructs.