08-js-uvod/08-js-control-flows.html

<!DOCTYPE html>

<html>

<head>
	<meta charset="utf-8" />
	<title>JS control flows</title>
</head>


<body>
	
	<h1>JS control flows</h1>


	<script>
	
	//IF ELSE
	
	// boolean
	var yesno = true;
	
	
	//IF ELSE
	if (yesno) {
		console.log('yes');
	} else {
		console.log('yes');
	}
	
	//IF ELSE
	// string
	var love = "i felt in love with...";
	
	if (love) {
		console.log('heaven');
	} else {
		console.log('hell');
	}
	
	
	// IF - ELSE IF - ELSE
		// number
	var magic = 7;
	
	if (magic==7) {
		console.log('seven');
	} else if (magic==5) {
		console.log('hell');
	}
	
	
	// SWITCH - CASE
	// pokud se nepouzije break, vyraz se vyhodnocuje vicekrat
	// samozrejme jde nahradit if-else if-else
	switch (magic) {
	case 7:
		console.log('switch case 7')
		//break;
	case (magic > 1):
		console.log('switch case magic>1')
		//break;
	default:
		console.log('default')
	}
	
	
	// TRY - CATCH - FINALLY
	// zachytavani vyjimek
	try {
		
		throw "bogus"; // vyhodi se vyjimka (at uz to udelame my, nebo nase aplikace)
		
	} catch(e) { // zachytime vyjimku
		
		console.log('exception catched'); //neco udelame
		
	} finally {
		
		// finally se provede VZDY, at uz nastala nejaka vyjimka, nebo ne
		// pouziva se typicky  na uzavirani socketu, spojeni do databaze, uzavreni pointeru na soubor, apod.
		// zkuste zakomentovat throw v radku nahore, uvidite, ze se tohle provede vzdy
		console.log('finally'); 
		
	}
	
	
	</script>

	<h2>See the results in JS console in your browser</h2>

</body>

</html>