为什么在if语句中首先检查“false”是否合适？

Question

For example the following code tests for false first then truth. Is there any performance benefits or time saving doing this?

if (!touch('some_file.txt', $time)) {
    echo 'Whoops, something went wrong...';
} else {
    echo 'Touched file with success';
}

instead of

if (touch('some_file.txt', $time)) {
    echo 'Touched file with success';
} else {
    echo 'Whoops, something went wrong...';
}

Answer 1

You can check on truth first but in main cases you would interact your code if false (for example file doesn't exists so you can put return false in if block.

And if you use if (touch()) you have to write many code in {} block

Compare:

if (touch(file)) {
    //do something...
    // do domething else...
    if (file contensts) {
        //do something....
        //and so on...
        if() {
           // you can continue yourself...
        }
    }
    // continue...
}

and

if (!touch(file)) {
    throw new Error('some error');
    // or return false
}

//do something...
// do domething else...

if (!contents(file)) {
    return false;
}

// continue...

So for stick on one style everyone check on false first