Languages-C & C Plus Plus [3i Infotech Placement]: Sample Questions 171 - 173 of 354

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Question 171

C & C Plus Plus
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Describe in Detail

Essay▾

What is a scope resolution operator?

Explanation

• The scope resolution operator “::” is used to qualify hidden names.
• We can use the unary scope operator if a namespace scope or global scope name is hidden by an explicit declaration of the same name in a block or class.

Example:

1. intcount=0;
2. intmain(void)
3. {
4.     intcount=0;
5.     :: count =1;
6.     count =2;
7.     return0;
8. }

Question 172

C & C Plus Plus
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Describe in Detail

Essay▾

What is the output of the following program?

1. main ()
2. {
3.     inti=10,j=20; j =i, j?(i,j)?i:j:j; printf("%d %d",i,j);
4. }

Explanation

In the program

 int i = 10, j = 20; Given the integer variable i = 10 and j = 20 j = i, j? (i, j) ? i: j: j; The ternary operator (? :) is equivalent for if-then-else statement.So, the question can be written as:if (i, j){if (i, j) j = i;else j = j;} else j = j; printf ( “% d % d” , i, j) ; Printf prints the value of i and j

Question 173

C & C Plus Plus
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Describe in Detail

Essay▾

What is the output of the program given below

1. main ()
2. {
3.     signedchari =0;
4.     for (; i>= 0; i ++ );
5.     printf ( “%d” i);
6. }

Explanation

• In the program define the signed char
• Signed char represents integers from -128 to 127.
 signed char i = 0; Define the signed character variable i = 0 for (; i >= 0; i ++) ; The semicolon at the end of the for loop.The initial value of the i is set 0.The inner loop executes to increment the value from 0 to 127 (the positive range of char) and then it rotates to the negative value of -128.The condition in the for loop fails and so comes out of the for loop. printf ( “% d” i) ; It prints the current value of I that is -128.