31. What will be the output of the following C code?
    

    #include <stdio.h>
        int main()
        {
            printf("Hello Interview Mania! %d \n", num);
            return 0;
        }
    

1. 1. Hello Interview Mania! num

   
   
   

   2. Compilation Error

   
   
   

   3. Hello Interview Mania!

   
   
   

   4. Hello Interview Mania! followed by a garbage value

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   It results in an error since num is used without declaring the variable num.

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32. Which of the following is not a valid C variable name?

1. 1. int $main;

   
   
   

   2. int var;

   
   
   

   3. float price;

   
   
   

   4. int num;

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   Since only underscore and no other special character is allowed in a variable name, it results in an error.

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33. Which of the following is true for variable names in C?

1. 1. Variable can be of any length

   
   
   

   2. Variable names cannot start with a digit

   
   
   

   3. It is not an error to declare a variable to be one of the keywords(like goto, static)

   
   
   

   4. They can contain alphanumeric characters as well as special characters

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   According to the syntax for C variable name, it cannot start with a digit.

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34. Which is valid C expression?

1. 1. int $new_n = 20;

   
   
   

   2. int new n = 20;

   
   
   

   3. int n = 20;

   
   
   

   4. int new_n = 20;

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   Space, comma and $ cannot be used in a variable name.

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35. Which of the following is not a valid variable name declaration?

1. 1. #define PI 3.14

   
   
   

   2. int PI = 3.14;

   
   
   

   3. double PI = 3.14;

   
   
   

   4. float PI = 3.14;

   
   
   

   5. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   #define PI 3.14 is a macro preprocessor, it is a textual substitution.

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