Use single quotes for strings and integers, this is true for both

Question

<?php

$str='18.8';

if(is_numeric($str)){

echo 'zheng';

}else{

echo 'jia';

}

if(is_string($str)){

echo 'zheng';

}else{

echo 'jia';

}

?>

Answer 1

• The parameter of the is_numeric() function is a number or a numeric string. Your parameter '18.8' is a numeric string and meets the conditions, so it returns "true";

• What you want to test is '18.8', you should use: is_float() function to test. If you want to test integer, please use is_int()

• More usage, Can parameter PHP User Manual