Sizeof(char[]);

[JohnRobert]

G'day,

I have the following code...

Code: Select all

void writeStr(char message[]){
	for(int x = 0; x<sizeof(message)-1; x++){
		txByte(TXD, (int)message[x]);
	}
}

The IDE is telling me: "invalid application of `sizeof'"

Why is this, and how to fix it?

Thanks,

John

[pstnotpd]

In ANSI C an array is passed as a pointer to the first element, i.e. by reference

I think the issue is you're trying to pass an un-sized array so the sizeof function cannot be aware of the size.

Examples usually pass the actual size of the array along with the array itself.

i.e.

Code: Select all

void writeStr(char message[],int arr_size) {
....

I've also found examples where you specify the size in the parameter, but as you appear to want flexibility in size this would not be an option.