Falsy values

by Kumar Sidharth

CSS

body {
  background: black;
}

JavaScript

if (check) {
  alert("check undefined");
}

var check;
if (check) {
  alert("check defined");
}

check = "";
if (check) {
  alert("check is null string");
};

check = " ";
if (check) {
  alert("check is string with space");
};

check = null;
if (check) {
  alert("check is string with space");
};

/*
function setCookie(name,value,days) {
    var expires = "";
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days*24*60*60*1000));
        expires = "; expires=" + date.toUTCString();
    }
    document.cookie = name + "=" + (value || "")  + expires + "; path=/";
}
function getCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}
function eraseCookie(name) {   
    document.cookie = name+'=; Max-Age=-99999999;';  
}
setCookie("roseIndia","http%3A%2F%2Fwww.roseindia.net",2);
alert(decodeURIComponent(getCookie("roseIndia")));*/