Java - arrays and String methods

Which of these is a correct way of declaring an array of integers?

• int[] arrayA = new int[10];

• int arrayB = new int[20];

• int arrayC[] = int[30];

• int[] arrayD = new int[40]

Suppose you create a typical array of Strings, containing the subjects you will see next year. Which of the following is NOT true.

• You may remove one of the subjects (it will be replaced by null).

• You may add another subject to the array.

• You may replace one subject with another one different.

• You may copy the contents of that array into another array with the same size.

Which are Java's primitive data types?

• byte, short, int, long, float, double, boolean, char, String

• byte, short, int, long, float, double, boolean, char, array

• byte, short, int, long, float, double, boolean, char, String, array

• byte, short, int, long, float, double, boolean, char

Suppose the variable 'word' stores a String more than 2 letters long.

Suppose the variable 'number' stores an int greater than 4.

What is the correct way to replace 'word' with itself repeated 'number' times?

• word = word.repeat(number);

• word = word.repeat(number+1);

• word += word.repeat(number);

• word = word.repeat(number-1);

How to get the first letter of a String saved in the variable 'abc'?

• abc.get(1);

• abc[1]

• abc.substring(0);

• abc.substring(0,1);

You want to relabel your company from "9lionz" to "10lionz".

Which of these ways are valid ways to achieve that?

• company = "10lionz";

• String company = "10lionz";

• company.substring(0,1) = "10";

• company += "10" - "9";

The code is supposed to return the initials from an array of names... Why is it not working properly?

• The return type should be an array of Strings, not int[].

• The substring method ca only be applied to Strings, not arrays themselves.

• The substring should look the first letter always: .substring(0,1);

• The method should return initials.

How to code a conditional that verifies if a string called 'mystery' contains a website ending in ".com"?

• if (mystery.substring(-4,-1) == ".com")

• if (mystery.substring(-4,-1).equals(".com"))

• if (mystery.substring(mystery.length-4) == ".com")

• if (mystery.substring(mystery.length-4).equals(".com"))

What is the output of this code inside the main method?

int[] myNums;

System.out.println(myNums[0]);

• null

• There's no output.

• An error appears.

• 0

What is the output of this code inside the main method?

int[] myNums = new int[3];

System.out.println(myNums[1]);

• null

• There's no output.

• An error appears.

• 0