Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
663 views
in Technique[技术] by (71.8m points)

php false place in condition

Usually comparing with false is done like this where false is on right side:

if(strpos($str, 'php') !== false) {
    // code
}

But I have also noticed at various places false on left side:

if(false !== strpos($str, 'php')) {
    // code
}

As far as I understand, they are same then why some people put false on left side? Is there anything special about it, something I am missing ?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Thats something inattentive developers invented

The "problem"

if ($var = false) { /* code */ }

The solution

if (false = $var) { /* code */ }

Latter one will fail and thus the developer sees, that he misses an additional =, !, ... here


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

2.1m questions

2.1m answers

60 comments

56.8k users

...