if/else is not working in foreach loop in php

I'm new in PHP and I don't loop through all records using if/else statement in foreach loop.

$string = "a , b , 1, 2, 3, c, d, e";

$string = explode(' , ', $string);

foreach ($string as $value) {


    if(is_int($value)){

        echo 'Int ' . $value . '<br>';

    }else{


        echo 'Char ' . $value . '<br>';
    }


}

I get this result from above code,

Output

Char a
Char b
Char 1, 2, 3, c, d, e

I expected following result, so kindly help me to figure out. Thanks

char a
char b
int 1
int 2
int 3
char c
char d
char e