检查变量是否在前10个字符中有任何空格

Question

What is the best way to check if the string has any spaces in the first 10 characters?

$value = "cdjfvdkvnfkjvnfjnbjfnjn";

Answer 1

Use strpos():

if (strpos(substr($string, 0, 1), ' ') !== FALSE) {
    // has whitespace
}

Or preg_match():

if(preg_match('/\s/', substr($string, 0, 10))) {
    // has whitespace
}

The advantage of preg_match() over strpos() is that it can detect any kind of whitespace not just space characters. \s is a shorthand representation for the character class [ \t\f ].