SKEE1103-Test 2 Subjective Questions

The scope of a variable can be defined as the accessibility of a variable in the program. Referring to the Figure 1, determine the program execution output of the C code. (10 marks)

Answer explanation

Num1 = 1

Num2 = 1

Num1 = 2

Num2 = 2

Num1 = 5

An array is defined as the collection of similar type of data items stored at contiguous memory locations. The C program shown in Figure 2 has an array consists of six (6) elements.

 

a)      The C code in line 4 seems to be incorrect. Rewrite the correct C code in line 4. (2 marks)

 

b)      Determine the output of line 6.  (2 marks)

 

c)      Complete the C code in line 10 to display array element values using the for loop. (2 marks)

 

d)     Determine the output of line 10 to incorporate changes in Q2(c). (2 marks)

 

e)      Assuming the integer data type is 32-bit, determine the output of line 13. (2 marks)

Answer explanation

a) int arr[6] = { 2, 7, 3, 1, 5, 9 };

b) 15

c) printf ("%d\t", arr[i]); 

d) 2  7  3  1  5 

e) 24

Structure is a way to group several related variables in various data types into one place. Ali is trying to create a C code with structure as shown in Figure 3 but encountered compilation error. By using the code line number, identify at least five (5) incorrect statements in the program and provide the correct answers.

(Note: You may use a table to answer this question.) (10 marks)

Answer explanation

Line 3: struct UTM

Line 7: };

Line 9: struct UTM a;

Line 10: strcpy(a.name, "C program");

Line 11: a.code = 2033;

Line 12: printf("%s", a.name);

Line 13: printf(“%d”, a.code);

Functions are used to perform certain actions, and they are important for program modularity and code reusability. By referring to the C code shown in Figure 4, answer the following questions.

a)      Complete the ‘Function Declaration’ in line 2. (3 marks)

 

b)      State the correct ‘Function Call’ in line 8. (3 marks)

 

c)      Which lines of code is the ‘Function Definition’ of the program? (2 marks)

 

d)     In line 15, the ‘return c’ statement returns the addition value of ‘a + b’ to which line of code? (2 marks)

Answer explanation

a) int add(int a, int b);  

b) Ans: add_result = add (a, b);   

c) Line 10-16 

d) line 8 (call function) 

Union is a special data type in C that allows to store different data types in the same memory location. By referring to the C code shown in Figure 5, answer the following questions.

 

a)      Declare a variable named ‘Var’ in line 10 with union data type of ‘Data’. (2 marks)

 

b)      Assign a value of 55 and 10.5 to the union member of ‘Var’ as declared in lines 3 and 4, respectively. (4 marks)

 

c)      Determine the output of line 12. (2 marks)

 

d)      Given the following line code, determine the output value of ‘Sat’.  (2 marks)

enum week{Mon = 0, Tue, Wed, Thur=4, Fri, Sat, Sun};

Answer explanation

a) union Data Var; 

b) Var.i = 55, Var.f = 10.5; 

c)  10

d)  Output value at ‘Sat’ = 6

Array is a compound data type in C program which can store and process multi-dimensional data.

 

a)     Declare a single dimension of floating point array, named ECG_sample, which could store total of 1000 data.  

b)    Declare a 2-dimension array, named A, with size and value as shown in below:

c)    Write a C code segment to sum up only the 2^nd column value, which is {2, 5, 8} in matrix A using single for loop only.

Answer explanation

a) float ECG_sample[1000];                        

 

b) int A[3][3] = {1,2,3,4,5,6,7,8,9};                 

 

c) int i = 0, sum = 0;                                     

    for (i=0, i<3, i++)                                      

    {

           sum+=A[i][1];                                       

     }

 

Structure is another user defined data type available in C that allows combination of data items from different datatype and usually used to represent a record.   [10 marks]

 

a)     Define a structure data type, named patient_record where it consists of three data members, one is name with character array that could store 30 alphabets, one is age with integer datatype, and another one is treatment_cost with float datatype. [5 marks]

b)    Declare an array of structure patient_record, named Wad11, which could store total of 50 patient records. [2 marks]

 

c)     Assume that now for the 10^th record of Wad11, you want to update the elements of name to
P. Ramlee, age to 80, and treatment_cost to 3200.00. Write the C code segment to perform this value assignment.

Answer explanation

a)   struct patient_record                             

       {

            char name[30];                                

            int age;                                           

            float treatment_cost;                       

        };                                                        

 

b) struct patient_record Wad11[50];              

                                                                 

c) strcpy(Wad11 [9].name, "P. Ramlee");       

    Wad11 [9].age = 80;                               

    Wad11 [9].treatment_cost = 3200.00;       

A pointer is a very useful concept in C program for indirect object access and dynamic memory allocation. [12 marks]

 

a)     Declare a pointer, named obj_ptr, which point to a variable of float datatype. [2 marks]

 

b)    Assign the memory address of a double variable, named cost, to the obj_ptr. [2 marks]

 

c)     Update the value of cost to 9999.9999 using indirect data access approach by de-referencing the obj_ptr. [2 marks]

 

d)    Based on the C code fragment and memory diagram, complete the table below.

Answer explanation

a) float obj_ptr;                             

b) obj_ptr = &cost;                         

c) obj_ptr = 9999.9999;                  

d) (i) 0x11223344

(ii) 0x12345678

(iii) 2120

(iv) 0x20000002

(v) 80

(vi) 0x11223344

 

There are four (4) printf() in the following coding to display the value of variable a. Please provide the output of variable a in each printf().

Answer explanation

(a) 30         

(b) 160             

(c) 30               

(d) 80

The compound data type in C programming consists of array and structure. [25 marks]

 

a)     Declare a single dimension of floating point array, named ECG_sample, which could store total of 1000 data. [2 marks]

 

b)    Declare a 2-dimension array, named matrix, with size as shown in diagram. [3 marks]

 

c)     Write a C code segment to sum up all the elements in matrix using for loop.   [5 marks]

 

d)    Write a C code segment to sum up only the 2^nd row value, which is {6, 7, 8, 9, 10} in matrix using for loop.   [5 marks]

 

e)     Define a structure data type, named PC where it consists of three data members, one is brand with character array that could store 30 alphabets, one is quantity with integer datatype, and another one is price with float datatype. [5 marks]

 

 

f)     Declare an array of structure PC, named sales, which could store total of 30 PC records. [2 marks]

 

g)    Assume that now for the very first records of sales, you want to update the PC elements of brand to Surface3, quantity to 50, and price to 3200.00. Write the C code segment to perform this value assignment. [3 marks]

Answer explanation

a) float ECG_sample[1000];                        

b) int matrix[3][5] ;                                      

c) int i=0, j = 0, sum = 0;                         

for (i=0; i < 3; i++)                               

    {

            for (j=0; j < 5; j++)                            

            {

                sum = sum + matrix[i][j];              

            }

     }

 

d)    int i=0, j = 0, sum = 0;                          

        for (j=0; j < 5; j++)                               

        {

                sum = sum + matrix[1][j];             

        }

      

 e)   struct PC                                              

       {

            char brand[30];                                

            int quantity;                                     

            float price;                                      

        };                                                        

 

f) struct PC sales[30];                                 

g) strcpy(sales[0].brand, "Surface3”);   

   sales[0].quantity = 50;                        

   sales[0].price = 3200.00;