# Languages-C & C Plus Plus [3i Infotech Placement]: Sample Questions 177 - 179 of 354

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## Question 177

C & C Plus Plus
Edit

### Write in Short

What are the advantages of using unions?

### Explanation

• Advantages is in terms of the memory.
• If a union & structure have one int and one float, then the size of the structure is sum of its members-10 (2 ⚹ 3 + 4) , the size of the union is only 4- that is the size of its largest member (the size of the float, the largest one in this union) .

## Question 178

C & C Plus Plus
Edit

### Write in Short

1. `main ()`
2. `{`
3. `    printf (“ab”);`
4. `    printf (“⧵bsi”);`
5. `    printf (“ha”);`
6. `}`

### Explanation

• In a program = new line
• ⧵b = backspace
• = linefeed or carriage return⧵
 printf ( “ab” ) ; First print to ab printf ( “⧵bsi” ) ; Now the handle backspace(NOTE: that even through it is “non-erase” , the next character to be output would overwrite what was backspaced over)Now print asi printf ( “ha” ) ; Now, a carriage return means to go back to the beginning of the lineSo, the “ha” overwrites the “as” in “asi”
• So, the answer is “hai”

## Question 179

C & C Plus Plus
Edit

### Write in Short

What is the output of the following program?

1. `main ()`
2. `{`
3. `    int i =0;`
4. `    int j =0;`
5. `    if (i && j ++ )`
6. `    printf ( “%d..%d”, i ++, j);`
7. `    printf(” %d..%d”, i, j);`
8. `}`

### Explanation

In the program

 int i = 0;int j = 0; Define the value of i is 0 and j is 0- this information is enough to determine the truth-value of the boolean expression.So, the statement following the if statement is not executed. printf ( “% d. . % d” , i, j) ; The values of i and j remain unchanged and get printed.

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