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<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Operators</h1>
<h2>The typeof Operator</h2>

<p>The typeof operator returns the type of a variable, object, function or expression:</p>

<p id="demo"></p>

<script>
document.getElementById("demo").innerHTML = 
"'John' is " + typeof "John" + "<br>" +
"3.14 is " + typeof 3.14 + "<br>" +
"NaN is " + typeof NaN + "<br>" +
"false is " + typeof false + "<br>" +
"[1, 2, 3, 4] is " + typeof [1, 2, 3, 4] + "<br>" +
"{name:'John', age:34} is " + typeof {name:'John', age:34} + "<br>" +
"new Date() is " + typeof new Date() + "<br>" +
"function () {} is " + typeof function () {} + "<br>" +
"myCar is " + typeof myCar + "<br>" +
"null is " + typeof null;


// !isNaN(34) // returns true

// integer or float

var v1 = 3.14;

 if( typeof v1 === 'number' )
 {
	document.getElementById('demo').innerHTML = " Good ";
 
 }
 
 
 function checkNumber1(x) 
 {

    let regexPattern = /^-?[0-9]+$/;
    
    // check if the passed number is integer or float
    let result = regexPattern.test(x);
    
	var mess;
	
    if(result) 
	{
       // console.log(`${x} is an integer.`);
	   mess = '${x} is an integer.';
	   console.log('${x} is an integer.');
    }
    else 
	{
       // console.log(`${x} is a float value.`)
	   mess = '${x} is a float value.';
	   console.log('${x} is a float value.');
    }
	
	document.getElementById('demo').innerHTML = mess;

}


function checkNumber2(x) {

    // check if the passed value is a number
    if(typeof x == 'number' && !isNaN(x)){
    
        // check if it is integer
        if (Number.isInteger(x)) {
            console.log(`${x} is integer.`);
        }
        else {
            console.log(`${x} is a float value.`);
        }
    
    } else {
        console.log(`${x} is not a number`);
    }
}


function isNegative(num) 
{
  if (typeof num === 'number' && Math.sign(num) === -1) 
  {
    return true;
  }

  return false;
}

 
 checkNumber1(44);
 
 checkNumber1(3.4);
 
 
 checkNumber2('hello');
checkNumber2(44);
checkNumber2(3.4);


console.log(isNegative(-5) );
console.log(isNegative(5) );


</script>

</body>
</html>