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# operators

```function paternChck(numbers){
if(numbers.length !== 8 || numbers.length !== 7 ){
return false;
}
}
```

why is that code not working? Why do i need to use less or greater here to make the code working.

when passing string like "12345678"

Okey I think I found the solution :) " NOT acts on one boolean expression (rather than two): ! means NOT. Results in true if the expression is false."

God that one gave my a headache :)

Hi Ireneusz,

What is this function supposed to do? Maybe you can get help with using better logic if you describe what it's supposed to do.

The `!` in javascript has multiple uses. The way you have described it in your answer is as the logical NOT operator and not the same as how you're using it in your code.

`!` can act as a unary operator where it takes 1 operand.

```var someBoolean = true;
!someBoolean; // this evaluates to false
```

How you're using it in your code, `!==`, is as the strict not equal to comparison operator which requires operands on both sides.

So `numbers.length !== 8` is going to evaluate to true if the length is not equal to 8.

```9 !== 8; // true
8 !== 8; // false
```

What your `if` condition is saying is "if the length is strictly not equal to 8 OR the length is strictly not equal to 7"

Your `if` condition will always be true because at least one side of the logical OR operator will always be true. In order to be false, both sides have to be false, `false || false` which means the length has to be both 8 and 7 at the same time, which it can't be.