Literals & Variables(Computer Science > Java Program ) Questions and Answers
Question 1.
What is the output of this program?
class dynamic_initialization { public static void main(String args[]) { double a, b; a = 3.0; b = 4.0; double c = Math.sqrt(a * a + b * b); System.out.println(c); } }
5.0
25.0
7.0
Compilation Error
Explanation:-
Answer: Option A. -> 5.0
Variable c has been dynamically initialized to square root of a * a + b * b, during run time. output: $ javac dynamic_initialization.java $ java dynamic_initialization 5.0
Question 2.
Which of these is incorrect string literal? A. "Hello World" B. "Hello`setminus`nWorld" C. "`setminus`"Hello World`setminus`"" D. "Hello world"
5.0
25.0
7.0
Compilation Error
Explanation:-
Answer: Option A. -> 5.0
Answer: D Explanation:all string literals must begin and end in same line.
Question 3.
What is the output of this program?
class array_output { public static void main(String args[]) { int array_variable [] = new int[10]; for (int i = 0; i < 10; ++i) { array_variable[i] = i/2; array_variable[i]++; System.out.print(array_variable[i] + " "); i++; } } }
0 2 4 6 8
1 2 3 4 5
0 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10
Explanation:-
Answer: Option B. -> 1 2 3 4 5
When an array is declared using new operator then all of its elements are initialized to 0
automatically. for loop body is executed 5 times as whenever controls comes in the loop
i value is incremented twice, first by i++ in body of loop then by ++i in increment condition
of for loop. output: $ javac array_output.java $ java array_output 1 2 3 4 5
Question 4.
What is the output of this program?
class evaluate { public static void main(String args[]) { int a[] = {1,2,3,4,5}; int d[] = a; int sum = 0; for (int j = 0; j < 3; ++j) sum += (a[j] * d[j + 1]) + (a[j + 1] * d[j]); System.out.println(sum); } }
