Consider the following example:

```
$a='This is a test';

```

If I now do:

```
if(strpos($a,'is a') !== false) {
    echo 'True';
}

```

It get:

```
True

```

However, if I use

```
if(strpos($a,'is a') === true) {
    echo 'True';
}

```

I get nothing. Why is `!==false` not `===true` in this context
I checked the PHP docs on `strpos()` but did not find any explanation on this.