CS计算机代考程序代写 ITI 1121. Introduction to Computing II – subtitle

ITI 1121. Introduction to Computing II – subtitle

public class TestSwapArrayInt {

public static void swap(int[] xs) {

int[] ys;
ys = new int[2];

ys[0] = xs[1];
ys[1] = xs[0];

xs = ys;

}

public static void main(String[] args) {

int[] xs;
xs = new int[2];

xs[0] = 15;
xs[1] = 21;

swap(xs);

System.out.println(xs[0]);
System.out.println(xs[1]);

}
}

args

xs

main

15 21

Working memory for the method main.

public class TestSwapArrayInt {

public static void swap(int[] xs) {

int[] ys;
ys = new int[2];

ys[0] = xs[1];
ys[1] = xs[0];

xs = ys;

}

public static void main(String[] args) {

int[] xs;
xs = new int[2];

xs[0] = 15;
xs[1] = 21;

swap(xs);

System.out.println(xs[0]);
System.out.println(xs[1]);

}
}

args

xs

main

15 21

xs

ys

swap

Calling the method swap. The value of the actual parameter is copied to the formal
parameter.

public class TestSwapArrayInt {

public static void swap(int[] xs) {

int[] ys;
ys = new int[2];

ys[0] = xs[1];
ys[1] = xs[0];

xs = ys;

}

public static void main(String[] args) {

int[] xs;
xs = new int[2];

xs[0] = 15;
xs[1] = 21;

swap(xs);

System.out.println(xs[0]);
System.out.println(xs[1]);

}
}

args

xs

main

15 21

xs

ys

swap

21 15

Creating an array and saving the reference into the variable ys. Copying xs[1] into ys[0]
and xs[0] into ys[1].

public class TestSwapArrayInt {

public static void swap(int[] xs) {

int[] ys;
ys = new int[2];

ys[0] = xs[1];
ys[1] = xs[0];

xs = ys;

}

public static void main(String[] args) {

int[] xs;
xs = new int[2];

xs[0] = 15;
xs[1] = 21;

swap(xs);

System.out.println(xs[0]);
System.out.println(xs[1]);

}
}

args

xs

main

15 21

xs

ys

swap

21 15

Copying the content of ys into xs (the formal parameter of the method swap).

public class TestSwapArrayInt {

public static void swap(int[] xs) {

int[] ys;
ys = new int[2];

ys[0] = xs[1];
ys[1] = xs[0];

xs = ys;

}

public static void main(String[] args) {

int[] xs;
xs = new int[2];

xs[0] = 15;
xs[1] = 21;

swap(xs);

System.out.println(xs[0]);
System.out.println(xs[1]);

}
}

args

xs

main

15 21

Returning to the method main. The working memory for swap is destroyed. Printing
xs[0] and xs[1] (the local variable xs for the method main).