Int or not Int. How to fix the code?

Question

I would like the code below to return 'Int' the first time and 'Not int' the second time. Unfortunately it returns 'Not int' twice instead.

How can I fix this?

<?php
$test1='1';
if(is_int($test1)){
        echo "Int";
}else{
        echo "Not int";
}

echo "\n";

$test2='1a';
if(is_int($test2)){
        echo "Int";
}else{
        echo "Not int";
}
?>

`'1'` is a string, not an int. – NullUserException Oct 04 '12 at 16:48 — NullUserException, Oct 04 '12 at 16:48

Zulakis · Accepted Answer · 2012-10-04T16:53:45.400

6

By wrapping the number in quotation marks '1', you are declaring a string. Instead you got to use $test1 = 1;.

By using the PHP ctype_digit() function, you can check if a string only contains digits.
You could also use the is_numeric() function, which also returns true if the string contains a exponential part like +0123.45e6 or a hex value 0xFF.

edited Oct 04 '12 at 16:53

answered Oct 04 '12 at 16:48

Zulakis

7,859
10
42
67

Jason · Answer 2 · 2012-10-04T16:54:48.930

2

is_int - Find whether the type of a variable is integer Because you put the number in quotes, it is a string. Therefore is_int = false

is_numeric — Finds whether a variable is a number or a numeric string Because the string is actually a number, is_numeric will return true

So, change is_int to is_numeric and it works:

<?php
$test1 = '1';
if (is_numeric($test1))
{
    echo 'Int';
}
else
{
    echo 'Not int';
}

echo "\n";

$test2 = '1a';
if (is_numeric($test2))
{
    echo 'Int';
}
else
{
    echo 'Not int';
}
?>

edited Oct 04 '12 at 16:54

answered Oct 04 '12 at 16:49

Jason

1,192
7
8

It might be a good idea to provide explanation of difference between `is_int` and `is_numeric`. – Zbigniew Oct 04 '12 at 16:51
is_numeric will be proven true if 1e4 or 909.89 are given. – Wayne Whitty Oct 04 '12 at 16:52
It is also a good idea to omit the closing tag (`?>`) at the end of code, as [mentioned by the documentation](http://www.php.net/manual/en/language.basic-syntax.phptags.php) and [outlined at StackOverflow](http://stackoverflow.com/a/4499749/548696). – Tadeck Oct 04 '12 at 17:00

score 1 · Answer 3 · answered Oct 04 '12 at 16:48

1

Use ctype_digit() instead.

ctype_digit('1'); // True
ctype_digit('1a'); // False

answered Oct 04 '12 at 16:48

Kemal Fadillah

9,760
3
45
63

score 0 · Answer 4 · answered Oct 04 '12 at 16:49

0

change

 $test1='1';

to

 $test1=1;

answered Oct 04 '12 at 16:49

Afshin

4,197
3
25
34

Int or not Int. How to fix the code?

4 Answers4