|
(a) Declare a pointer to an array of
characters, called MyChar, the length of which should not be decided
until allocation time. [1 mark]
(a) char* myChar[]; [1 mark]
(b) Give the results of executing the
following function calls, and explain your answer:
(i) printf("%d\n", strlen("Hello World\n")); [2
marks]
(ii) printf("%d\n", sizeof("Hello World\n"));
[2 marks]
(b) (i) • 12 (1 mark)
• This is the length of the string, including the newline but
excluding the trailing null; (1 mark)
[2 marks]
(ii) • 13 (1 mark)
• This is the length of the string, including the newline and
the trailing null; (1 mark)
(c) Implement a function, called Convert,
which takes a pointer to a string s, and converts all of the lower
case characters in the string to upper case characters. All upper
case characters should remain unchanged. Note that the ASCII values
of A to Z is the range 65 to 90, and a to z is 97 to 122. [5 marks]
(c) A sample definition of Convert follows:
void Convert(char* s) {
for(s; s!= NULL; s++)
if(atoi(s) >= 65 && atoi(s) <= 90)
*s= itoa(atoi(s)+32);
}
And the following marking scheme should be used:
• An appropriate function signature, complete with const pointer;
(1 mark)
• A loop to iterate along the strong, bound by the null terminating
character; (1 mark)
• A test to see if the current character is in the required range,
by taking the ascii value of the character; (1 mark)
• Calculating the new ascii value; (1 mark)
• Assigning the new character having calculated it from its ascii
value; (1 mark)
[5 marks]
(d) Implement a function, called StrCaseCmp,
such that it takes in two pointers to strings, s and t and compares
the two strings, ignoring the case of the individual characters. The
function should return an integer less than, equal to or greater than
zero if s is found, respectively, to be less than, equal to or greater
than t. [5 marks]
(d) A sample definition of StrCaseCmp follows:
int StrCaseCmp(const char* s, const char* t) {
char *a= (char*)malloc(strlen(s));
char *b= (char*)malloc(strlen(t));
strcpy(a, s);
strcpy(b, t);
Convert(a);
Convert(b);
return strcmp(a, b);
}
And the following marking scheme should be used:
• A suitable function signature complete with const parameters;
(1 mark)
• Declaring local temporary strings to work with, and ensuring
they are long enough;
(1 mark)
• Copying the parameters into the local strings; (1 mark)
• Converting both strings to upper case characters only; (1 mark)
• Returning the result of comparing both upper case strings;
(1 mark)
[5 marks]
|