računalniška znanja
7 naročnikov
7 naročnikov
me zanima, katera znanja so (in bodo) uporabna, da lahko dobimo "dobro" zaposlitev- kaj se splača učiti?
lp
33 odgovorov
ASP, .NET, VB, C#, MS SQL, PHP, Java
so to programski jeziki?
je kaksen link na "screenshot"-kako zgleda en projekt?
lp
za javo sem dobil to kodo. kaj pa je rezultat oz izdelek? za katere stvari se uporabljajo ti jeziki?
/*
* Screenshot.java (requires Java 1.4+)
*/
import java.awt.;
import java.awt.image.;
import java.io.;
import javax.imageio.;
public class Screenshot {
public static void main(String[] args) throws Exception {
// make sure we have exactly two arguments,
// a waiting period and a file name
if (args.length != 2) {
System.err.println("Usage: java Screenshot " +
"WAITSECONDS OUTFILE.png");
System.exit(1);
}
// check if file name is valid
String outFileName = args[1];
if (!outFileName.toLowerCase().endsWith(".png")) {
System.err.println("Error: output file name must " +
"end with \".png\".");
System.exit(1);
}
// wait for a user-specified time
try {
long time = Long.parseLong(args[0]) * 1000L;
System.out.println("Waiting " + (time / 1000L) +
" second(s)...");
Thread.sleep(time);
} catch(NumberFormatException nfe) {
System.err.println(args[0] + " does not seem to be a " +
"valid number of seconds.");
System.exit(1);
}
// determine current screen size
Toolkit toolkit = Toolkit.getDefaultToolkit();
Dimension screenSize = toolkit.getScreenSize();
Rectangle screenRect = new Rectangle(screenSize);
// create screen shot
Robot robot = new Robot();
BufferedImage image = robot.createScreenCapture(screenRect);
// save captured image to PNG file
ImageIO.write(image, "png", new File(outFileName));
// give feedback
System.out.println("Saved screen shot (" + image.getWidth() +
" x " + image.getHeight() + " pixels) to file \"" +
outFileName + "\".");
// use System.exit if the program hangs after writing the file;
// that's an old bug which got fixed only recently
// System.exit(0);
}
}
Ok če si mlajši od 10 let potem se ti tole vprašanje spregleda. :D
Sicer pa sprašuješ rudarje čemu služi kramp.
No pa vseeno ti bom poskusil razložiti:
Ker računalniki ne razumejo preveč dobro človeškega glasu, jim z določenimi ukazi povemo kaj naj naredijo.
Ti ukazi so standardizirani (upam da ni pretežka beseda :D ) in vsi ukazi in pravila skupaj tvorijo zadevo, ki se ji reče programski jezik.
Torej s programskim jezikom mi ljudje povemo računalnikom kaj naj počnejo.
Primer 1. HTML
Če v beležici napišeš:
<html>
<head>
<title>OMG dela</title>
</head>
<body>
mar8 raztura HTML
</body>
</html>
in to shraniš kot uau.html ter poženeš z brskalnikom, ti bo izpisalo "mar8 raztura HTML" in že se lahko pohvališ mami kašen heker si in da jutri bo padel Pentagon.
Primer 2. ASP
Če v beležici napišeš:
<html>
<head>
<title>OMG dela</title>
</head>
<body>
<%=time()%>
</body>
</html>
in to shraniš koz omg.asp ter naložiš na strežnik (ne sprašuj kaj je to) ti bo vsakič ko boš stran osvežil izpisalo trenutni čas.
Primer 3. SQL
Emm raje ne, prvo naštudiraj zgornja dva primerčka. :D
In ko že sprašuješ za katere stvari se uporabljajo programski jeziki, je odgovor za programe ozr. aplikacije.
Mi ki smo na tem forumu programiramo predvsem spletne aplikacije, torej spletne strani po katerih dnevno brskaš npr. glasujzame.com, otroškivrtec.org, ...
frenky, HTML ni programski jezik :) ce sem pa se malo tecen, sta PHP in ASP skriptna jezika, SQL je pa poizvedbeni jezik :)
Ma sej sem vedel da se bo kdo vtaknil v to. Zdaj ga boste reveža samo še bolj zmedli. :D
Za HTML vem da ni, za ASP sem pa res mislil, da je programski jezik. Očitno sem skriptaš in ne programer.
Kaj pa C#?
C++ je pa ziher, ko sem bil "mlad" sem naredil igrico FreeCell iz ascii znakov in z miško. :D
Ma ja, sej res mal prevec kompliciramo :) Za nekatere skriptni jeziki so programski jeziki, za nekatere pa ne. Dajmo za poenostavitev tudi mi uporabljati termin programski jezik tudi za PHP in ASP...
HTML pa naj kar ostane opisni jezik :)
Vini samo, če posplošimo je skripta, ki se odvija na serverju dotični web program, ki ga prepozna samo server z določenim vmesnikom.
Je tako al se pošteno motim ? :)
Ja, PHP skripta potrebuje PHP interpreter za to, da jo lahko izvedemo. Ce nimas na strezniku PHP interpreterja, ti skripta ne pomaga cisto nic :) Ampak mislim, da to nima nobene veze s tem, ali PHP je ali ni programski jezik (lahko se tudi motim, nisem nek hud teoretik na tem podrocju). Mogoce nekaj copy/pastov z wikipedie:
Programming languages are used to facilitate communication about the task of organizing and manipulating information, and to express algorithms precisely. Some authors restrict the term "programming language" to those languages that can express all possible algorithms; sometimes the term "computer language" is used for more limited artificial languages.
Authors disagree on the precise definition, but traits often considered important requirements and objectives of the language to be characterized as a programming language:
* Function: A programming language is a language used to write computer programs, which instruct a computer to perform some kind of computation, and/or organize the flow of control between external devices (such as a printer, a robot, or any peripheral).
* Target: Programming languages differ from natural languages in that natural languages are only used for interaction between people, while programming languages also allow humans to communicate instructions to machines. In some cases, programming languages are used by one program or machine to program another; PostScript source code, for example, is frequently generated programmatically to control a computer printer or display.
* Constructs: Programming languages may contain constructs for defining and manipulating data structures or for controlling the flow of execution.
* Expressive power: The theory of computation classifies languages by the computations they can express (see Chomsky hierarchy). All Turing complete languages can implement the same set of algorithms. ANSI/ISO SQL and Charity are examples of languages that are not Turing complete yet often called programming languages.
Glede HTMLja:
Non-computational languages, such as markup languages like HTML or formal grammars like BNF, are usually not considered programming languages. It is a usual approach to embed a programming language into the non-computational (host) language, to express templates for the host language.