Computer Knowledge

Programming Output Evaluation

1,721 Questions

Programming output evaluation tests the ability to trace code execution in languages like C, Java, and SAS. It focuses on arrays, loops, pointers, and data type conversions. These technical questions are standard in computer knowledge sections for IT officer and bank exams.

Java string bufferC language pointersLoop execution outputsData type conversionsMacro variable evaluation

Programming Output Evaluation Questions

Multiple choice technology programming languages

class JJF3 { public static void main(String args[]) { System.out.print(Integer.toBinaryString(Byte.MAX_VALUE)+","); System.out.print(Integer.toOctalString(Byte.MAX_VALUE)+","); System.out.print(Integer.toString(Byte.MAX_VALUE)+","); System.out.print(Integer.toHexString(Byte.MAX_VALUE)); }}

  1. Prints: 1111111,177,127,7f

  2. Prints: 11111111,377,256,ff

  3. Compile-time error

  4. Run-time error

  5. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Byte.MAX_VALUE is 127. In binary: 1111111 (7 bits). In octal: 177. In decimal: 127. In hexadecimal: 7f. The toBinaryString, toOctalString, toString, and toHexString methods produce these representations separated by commas.

Multiple choice technology programming languages

class JJF4 { public static void main(String args[]) { System.out.print(Long.toHexString(Byte.MAX_VALUE)+","); System.out.print(Long.toHexString(Character.MAX_VALUE)+","); System.out.print(Long.toHexString(Short.MAX_VALUE)); }}

  1. Prints: f,ff,7f

  2. Prints: f,ff,ff

  3. Prints: 7f,ffff,7fff

  4. Prints: ff,ffff,ffff

  5. Prints: 7fff,ffffff,7fffff

  6. Prints: ffff,ffffff,ffffff
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Byte.MAX_VALUE = 127 = 0x7f. Character.MAX_VALUE = 65535 = 0xffff. Short.MAX_VALUE = 32767 = 0x7fff. Long.toHexString converts each to hex string representation without leading zeros.

Multiple choice technology programming languages

class Identifiers { int i1; // 1 int _i2; // 2 int i_3; // 3 int #i4; // 4 int $i5; // 5 int %i6; // 6 int i$7; // 7 } Compile-time errors are generated at which lines?

  1. 1

  2. 2

  3. 3

  4. 4

  5. 5

  6. 6
Reveal answer Fill a bubble to check yourself
D,F Correct answer
Explanation

Java identifiers cannot start with # or %. Valid identifier characters are letters, digits, _, and $, but only letters, _, and $ can start an identifier. Lines 4 (#i4) and 6 (%i6) violate these rules.

Multiple choice technology programming languages

class A { void m1(int i) { int j = i % 3; switch (j) { case 0: System.out.print("0"); break; case 1: System.out.print("1"); break; default: assert j == 2; System.out.print(j); }} public static void main (String[] args) { A a = new A(); for (int i=5; i >= -1; i--) {a.m1(i);} }} Which statements are true?

  1. With assertions enabled it prints 210210-1 followed by an AssertionError message.

  2. With assertions enabled it prints 210210 followed by an AssertionError message.

  3. With assertions enabled it prints only 210210

  4. With assertions enabled it prints nothing.

  5. With assertions disabled it prints 210210-1

  6. With assertions disabled it prints only 210210
Reveal answer Fill a bubble to check yourself
B,E Correct answer
Explanation

When i is -1, j = -1 % 3 results in -1. In the switch, -1 goes to default. With assertions enabled, assert j == 2 fails because -1 != 2, throwing an AssertionError after printing "210210". With assertions disabled, it prints "-1".

Multiple choice technology programming languages

class C { String m1(int i) { switch (i) { case 0: return "A"; case 1: return "B"; case 2: return "C"; default: assert false; } } public static void main(String[] args) { C c = new C(); for (int i = 0; i < 4; i++) { System.out.print(c.m1(i)); }}} Which statements are true?

  1. With assertions enabled it prints ABC followed by an AssertionError message.

  2. With assertions disabled it prints ABC followed by an AssertionError message.

  3. Assertions should not be used within the default case of a switch statement.

  4. In this code example a throw statement must be used in place of the assert statement.

  5. Compile-time error
Reveal answer Fill a bubble to check yourself
D,E Correct answer
Explanation

The code contains a compile-time error because the switch statement inside m1 does not guarantee a return value for all paths if assertions are disabled. The compiler requires a return statement or a thrown exception after the switch block.

Multiple choice technology programming languages

What is the output of the follwing code snippet: $mystring = "The start text always precedes the end of the end text."; if($mystring =~ m/start(.*)end/) { print $1; }

  1. text always precedes the

  2. text always precedes the end of the end

  3. text always precedes the end of the

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Perl, the * quantifier is greedy by default. The pattern start(.*)end matches from the first "start" to the last "end" in the string. Thus, $1 captures everything between "start" and the final "end", which is "text always precedes the end of the".

Multiple choice technology programming languages

int p(char *a[])

  1. p is a pointer to a function that accepts an argument which is a pointer to a character and returns an integer quantity

  2. p is a function that accepts an argument which is a pointer to a character array and returns an integer quantity

  3. p is a function that accepts an argument which is a pointer to a character and returns a pointer to a 10 element integer array

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the declaration int p(char *a[]), p is a function that accepts an argument a, which is an array of pointers to characters (or a pointer to a character array), and returns an integer value.

Multiple choice technology programming languages

The initial value of an instance variable of type String which is not explicitly initialized in the program is --.

  1. null

  2. ""

  3. NULL

  4. 0
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Java automatically initializes instance variables (fields) to default values. For reference types like String, the default value is null, not an empty string or any other value. This behavior differs from local variables, which must be explicitly initialized before use.

Multiple choice technology programming languages

main(){ int i=100,j=10,k=20; int sum; float ave; char myformat[]="ave=%.2f"; sum=i+j+k; ave=sum/3; printf(myformat,ave); }

  1. Compile error

  2. ave=43.33

  3. link error

  4. ave= 43.00
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The sum is 100+10+20 = 130. Integer division 130/3 yields 43 (truncates toward zero). This integer is stored in float variable as 43.0, then printf with %.2f format shows 'ave= 43.00'. Option B is wrong because it shows 43.33, which would require floating-point division (130.0/3).

Multiple choice technology programming languages

struct aaa{ struct aaa *prev; int i; struct aaa *next; }; main(){ struct aaa abc,def,ghi,jkl; int x=100; abc.i=0;abc.prev=&jkl; abc.next=&def; def.i=1; def.prev=&abc; def.next=&ghi; ghi.i=2; ghi.prev=&def; ghi.next=&jkl; jkl.i=3; jkl.prev=&ghi; jkl.next=&abc; x=abc.next->next->prev->next->i; printf("%d",x); }

  1. 1

  2. 2

  3. 3

  4. nullpointer assignment
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Tracing the pointers: abc.next points to def, def.next points to ghi, ghi.prev points back to def, def.next points to ghi, and ghi.i equals 2. The entire expression evaluates to 2. Option A (1) would be def.i, and Option C (3) would be jkl.i.

Multiple choice technology programming languages

What is the output of the following? int main() { ... int *p=new int(87); ... }

  1. compile time error

  2. run time error

  3. p is initialized to 87

  4. space for an array of 87 integers is allocated
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In C++, new int(87) allocates memory for a single int and initializes it to 87. The pointer p points to this allocated int containing value 87. Option D would require new int[87](array syntax).