如何检查字符串是否包含特定的单词？

Consider:

$a = 'How are you?';

if ($a contains 'are')
    echo 'true';

Suppose I have the code above, what is the correct way to write the statement if ($a contains 'are')?

转载于:https://stackoverflow.com/questions/4366730/how-do-i-check-if-a-string-contains-a-specific-word