283). What will be the output of the following Java snippet, if attempted to compile and run this code with command line argument “java abc Rakesh Sharma”?
public class abc
{
int a=2000;
public static void main(String argv[])
{
System.out.println(argv[1]+" :-Please pay Rs."+a);
}
}
[A]Compile time error
[B]Compilation but runtime error
[C]Compilation and output Rakesh :-Please pay Rs.2000
[D]Compilation and output Sharma :-Please pay Rs.2000
Show Answer
Correct Answer: Compile time error
Notes:
Answer: a
Explanation: Main method is static and cannot access non static variable a.
284). What will be the output of the following Java snippet, if attempted to compile and execute?
class abc
{
public static void main(String args[])
{
if(args.length>0)
System.out.println(args.length);
}
}
[A]The snippet compiles, runs and prints 0
[B]The snippet compiles, runs and prints 1
[C] The snippet does not compile
[D]The snippet compiles and runs but does not print anything
Show Answer
Correct Answer: The snippet compiles and runs but does not print anything
Notes:
Answer: d
Explanation: As no argument is passed to the code, the length of args is 0. So the code will not print.
285). What will be the output of the following Java snippet, if compiled and executed with command line argument “java abc 1 2 3”?
public class abc
{
static public void main(String [] xyz)
{
for(int n=1;n
[A]1 2
[B]2 3
[C]1 2 3
[D]Compilation error
Show Answer
Correct Answer: 2 3
Notes:
Answer: b
Explanation: The index of array starts with 0. Since the loop is starting with 1 it will print 2 3.
286). What will be the output of the following Java code snippet running with “java demo I write java code”?
public class demo
{
public static void main(String args[])
{
System.out.println(args[0]+""+args[args.length-1]);
}
}
[A]The snippet compiles, runs and prints “java demo”
[B]The snippet compiles, runs and prints “java code”
[C]The snippet compiles, runs and prints “demo code”
[D]The snippet compiles, runs and prints “I code”
Show Answer
Correct Answer: The snippet compiles, runs and prints “I code”
Notes:
Answer: d
Explanation: The index of array starts with 0 till length – 1. Hence it would print “I code”.
287). What will be the output of the following Java snippet, if compiled and executed with command line “hello there”?
public class abc
{
String[] xyz;
public static void main(String argv[])
{
xyz=argv;
}
public void runMethod()
{
System.out.println(argv[1]);
}
}
[A]Compile time error
[B]Output would be “hello”
[C]Output would be “there”
[D]Output would be “hello there”
Show Answer
Correct Answer: Compile time error
Notes:
Answer: a
Explanation: Error would be “Cannot make static reference to a non static variable”. Even if main method was not static, the array argv is local to the main method and would not be visible within runMethod.
288). How do we pass command line argument in Eclipse?
public class abc
{
String[] xyz;
public static void main(String argv[])
{
xyz=argv;
}
public void runMethod()
{
System.out.println(argv[1]);
}
}
[A]Arguments tab
[B]Variable tab
[C]Cannot pass command line argument in eclipse
[D]Environment variable tab
Show Answer
Correct Answer: Arguments tab
Notes:
Answer: a
Explanation: Arguments tab is used to pass command line argument in eclipse.
289). Which class allows parsing of command line arguments?
public class abc
{
String[] xyz;
public static void main(String argv[])
{
xyz=argv;
}
public void runMethod()
{
System.out.println(argv[1]);
}
}
[A]Args
[B]JCommander
[C]Command Line
[D]Input
Show Answer
Correct Answer: JCommander
Notes:
Answer: b
Explanation: JCommander is a very small Java framework that makes it trivial to parse command line parameters.
290). Which annotation is used to represent command line input and assigned to correct data type?
public class abc
{
String[] xyz;
public static void main(String argv[])
{
xyz=argv;
}
public void runMethod()
{
System.out.println(argv[1]);
}
}
[A]@Input
[B] @Variable
[C]@Command Line
[D] @Parameter
Show Answer
Correct Answer: @Parameter
Notes:
Answer: d
Explanation: @Parameter, @Parameter(names = { “-log”, “-verbose” }, description = “Level of verbosity”), etc are various forms of using @Parameter
291). What will be the output of the following Java code snippet run as $ java Demo –length 512 –breadth 2 -h 3?
class Demo {
@Parameter(names={"--length"})
int length;
@Parameter(names={"--breadth"})
int breadth;
@Parameter(names={"--height","-h"})
int height;
public static void main(String args[])
{
Demo demo = new Demo();
new JCommander(demo, args);
demo.run();
}
public void run()
{
System.out.println(length+" "+ breadth+" "+height);
}
}
[A]2 512 3
[B]2 2 3
[C]512 2 3
[D]512 512 3
Show Answer
Correct Answer: 512 2 3
Notes:
Answer: c
Explanation: JCommander helps easily pass command line arguments. @Parameter assigns input to desired parameter.
292). What is the use of @syntax?
class Demo {
@Parameter(names={"--length"})
int length;
@Parameter(names={"--breadth"})
int breadth;
@Parameter(names={"--height","-h"})
int height;
public static void main(String args[])
{
Demo demo = new Demo();
new JCommander(demo, args);
demo.run();
}
public void run()
{
System.out.println(length+" "+ breadth+" "+height);
}
}
[A]Allows multiple parameters to be passed
[B]Allows one to put all your options into a file and pass this file as a parameter
[C]Allows one to pass only one parameter
[D]Allows one to pass one file containing only one parameter
Show Answer
Correct Answer: Allows one to put all your options into a file and pass this file as a parameter
Notes:
Answer: b
Explanation: JCommander supports the @syntax, which allows us to put all our options into a file and pass this file as a parameter.
/tmp/parameters
-verbose
file1
file2
$ java Main @/tmp/parameters