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Simplifying Switch Options

Simplifying Switch Options

C/C++ programmers are used to parsing command line arguments using the “int argc” and “char *argv[]” parameters to the main() function. Java programmers can use a similar syntax to greatly simplify the processing of optional switches:

 public class DemoSwitch {	// Optional switch - default is false	private boolean switch = false;	// Execution starts here	static public void main(String args[]) {		int argc = args.length;		// Number of command line parameters		int argv = 0;			// Index to first one		String parameter;		// Expected parameter			// Turn optional switch on if present in the command line    		if (argc > 0 && (switch = args[argv].startsWith("-s"))) {			// Skip for further processing			--argc;			++argv;		}    			// Continue processing command line parameters		if (argc > 0) {			parameter = args[argv];		} else {			System.err.println("Usage: java DemoSwitch [-s] ");			return;		}	        // place useful code here...    	}}

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