Java 17 Recipes

1-10. Passing Arguments via Command-Line
Execution
 Problem
You want to pass values into a Java application invoked via the java utility 
command line.
 Solution
Run the application using the java utility, and specify the arguments that you want to 
pass into it after the application name. If you’re passing more than one argument, each 
should be separated by a space. For example, suppose you want to pass the arguments to 
the class created in Listing 
1-8
.
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Listing 1-8. Example of Accessing Command-Line Arguments
public class PassingArguments {
public static void main(String[] args){
if(args.length > 0){
System.out.println("Arguments that were passed to the program: ");
for (String arg:args){
System.out.println(arg);
}
} else {
System.out.println("No arguments passed to the program.");
}
}
}
First, make sure to compile the program so that you have a .class file to execute. 
You can do that via the javac utility at the command line or terminal.
Therefore, open a command prompt or a terminal window for compiling and 
executing your Java class. Now issue a java command to execute the class and type 
some arguments on the command line following the class name. The following example 
passes two arguments.
java PassingArguments Luciano Manelli
You should see the following output.
Luciano
Manelli
Spaces separate arguments. Enclose strings in double quotes when you want to pass 
an argument containing spaces or other special characters. The following is an example.
C:\Users\lucky\OneDrive\Desktop>java PassingArguments "Luciano Manelli"
The output now shows just one argument.
Arguments that were passed to the program:
Luciano Manelli
The double quotes translate the "Luciano Manelli" string into a single argument.
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