Check that variable is a number

Question

How can I check that a variable is a number, either an integer or a string digit?

In PHP I could do:

if (is_int($var)) {
    echo \'$var is integer\'         


        

Answer 1

You should use

simple way to check whether given value is number by using "if condition"

function isInteger(value)      
{       
    num=value.trim();         
    return !(value.match(/\s/g)||num==""||isNaN(num)||(typeof(value)=='number');        
}

it will return true if the value which we are passing is an integer..

solved for     
value=""      //false null     
value="12"    //true only integers       
value="a"     //false     
value=" 12"   //false      
value="12 "   //false         
value=" "     //false space        
value="$12"   //false special characters 
value="as12"    //false