'i' was not declared in this scope

Projects Programming
1

void setup() {
// put your setup code here, to run once:
int i;
pinMode(11,OUTPUT);
}

void loop() {
// put your main code here, to run repeatedly:

while (i!=0){
digitalWrite(11,i);
i++
}

}

2

i was declared in setup(). When setup() is done i is destroyed. Thus i was not declared in the scope of loop().

Code tags, please use them?

3

Thanks. I forgot about code tags I'll use them from now on .
Thanks again.

4

Ok, but start now by editing your first post (the "pencil" button), select the code and press the "code" tag button ("</>"), then save. Thanks.

5

When you get an error that tells you “not declared in scope” you need to study scope and what it means. In brief and simplified:

You can declare things globally or locally.

Globally: normally at the beginning of the code outside any function ie not within any {}

Locally: inside a function ie between {}

The global variable will be visible everywhere in your code which can be handy but it also makes it vulnerable to change in a big complex code as all the code has access to it,

A local variables is created when the function runs and disappears when it completes so it can only be used within the function {}. This protects the variable from the rest of the code and is part of a concept called encapsulation

6

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