Comp Prog Finals

• Repetition of action is a fundamental concept in computer programming, allowing efficient handling of large amounts of data. In C, three statements – while, for, and do – facilitate repetitive actions.
• The while statement allows the programmer to specify an expression that must be true for the loop body to execute repeatedly until the condition becomes false.
• The do-while statement executes its body first and then tests whether it should continue or terminate based on the specified condition.
• In the for statement, the initialization, test, and increment/decrement expressions are executed once at the beginning of the loop, followed by repeated execution of the loop body as long as the test expression remains true.
• WHILE statement: syntax: while (expression) statement;//next statement;
• Fill the missing words:

  A) while

  B) next statement;

  C) false

  D) statement

  
• Fill the missing words:

  A) for

  B) initialization

  C) condition;

  D) increment

  E) statement;

  
• fill in the missing parts:

  A) nested for loop

  B) initialization1; condition1; increment1

  C) initialization2; condition2;

  D) statement;

  
• fill in the missing parts:

  A) do

  B) initialization; condition; increment

  C) statement;

  D) zero

  
• *Characteristics of an ARRAY:

  
  

  ▪ An array is a fixed-size, sequenced collection of elements of the same data type.
• *Characteristics of an ARRAY:

  
  

  ▪ It is a sequence of data items that are of the same type, indexable, and stored contiguously.
• *Characteristics of an ARRAY:

  
  

  ▪ Arrays represent a large number of homogeneous values
• Array Representation:

  ▪ Elements are individually addressed through subscripts.

  ▪ The array as a whole has a name, but each member can be accessed individually using its subscript.

  
  

  Index Form:

  Number[0], Number[1], ..., Number[19]

  Subscript Form:

  Number0, Number1, ..., Numbern-1
• a)Declaration and Definition:

  ▪ Array must be declared and defined before use.

  
  

  ▪ Syntax: storage class data-type array[expression];

  
  

  ▪ Examples:

  int ccmit[5];

  char bscs[30];

  float bsit[20];

  double ITCS[12];
• b)Initialization:

  ▪ Initialization is done at declaration.

  
  

  ▪ Example:

  int x[4] = {1, 2, 3};

  
  

  ▪ Default values: Unassigned elements are filled with zeros.
• c) Accessing Elements:

  
  

  ▪ C uses an index to access individual elements.

  
  

  ▪ Index is an integral value or expression.

  
  

  ▪ Example:

  scores[0], scores[i]
• d) Storing Values in Array:

  
  

  ▪ Declaration and definition only reserve space.

  
  

  ▪ Values must be initialized, read from the keyboard, or assigned.

  
  

  ▪ Example:

  scores[4] = 23;
• ● Introduction to Functions in C:

  
  

  ▪ Definition: A function is a section of a program that performs a specific task.

  
  

  ▪ Top-Down Approach: Effective problem-solving involves breaking down problems into manageable pieces using the function construct.
• Advantages of Using Functions:

  
  

  ▪ Top-Down Design: Fits naturally with a top-down design approach.

  
  

  ▪ Reusability: Functions can be used multiple times in a program and in different programs.

  
  

  ▪ Team Collaboration: Facilitates dividing programming tasks among a team of programmers.

  
  

  ▪ Modularity: Functions can be tested individually, simplifying the debugging process
• ● Function Declarations:

  
  

  ▪ Syntax: type function_name (parameter list)

  
  

  ▪ Examples:

  int ccmit (int bsit, int bscs);

  void ccmit ();

  float ccmit (float x, float y);
• ● Function Definitions:

  
  

  ▪ The code describing what a function does is called a function definition

  
  

  ▪ General Form:

  type function_name (parameter list)

  {

  declaration → local variables statement;

  }
• ● Local Variables to a Function:

  
  

  ▪ Variables declared in the function body are local to that function.

  ▪ Local variables are known only within their own code block.

  ▪ Exist only during the execution of the block in which they are declared.
• ● Global Variables to a Function:

  
  

  ▪ Known throughout the entire program and may be used by any piece of code.

  ▪ Declared outside of any function.

  ▪ Use sparingly to avoid unnecessary memory usage and potential errors
• ● The return Statement:

  
  

  ▪ Syntax: return; or return(expression);

  ▪ The value returned can be enclosed in parentheses
• ● Function Prototypes:

  
  

  ▪ Functions should be declared before use.

  ▪ Use functional prototypes for better code checking.

  ▪ Example: double sqrt(double);
• ● Giving Names to Parameters/Parameter Lists:

  
  

  ▪ Formal parameters are placeholders for actual parameters.

  ▪ Parameters in the function header are replaced by actual parameters when the function is called.
• ● Function Invocation and Call By Value:

  
  

  ▪ Programs start with main()

  ▪ Functions are invoked by writing their names and arguments in parentheses.

  ▪ All arguments are passed by value.
• ● Giving Names to Parameters/Parameter Lists:

  
  

  ▪ Formal parameters are placeholders for actual parameters.

  ▪ Parameters in the function header are replaced by actual parameters when the function is called.
• ● Call by Reference or Variable Parameters:

  
  

  ▪ To change the value of a variable in the calling environment, use pointers

  ▪ Pass the address of the variable to achieve "call by reference"
• ● STRING FUNCTIONS (string.h)

  ▪ COPY

  ○ stpcpy (string1, string2) / strcpy (string1, string2)

  ✓ Copies contents of string2 to string1.

  
  

  o strncpy (target, source, count)

  ✓ Copies up to count characters from source to target.

  
  

  o strxfrm(target, source, count)

  ✓ Copies up to count characters from source to target. Returns the length of source
• ▪ CONCATENATE

  
  

  o strcat (string1, string2)

  ✓ Concatenates string1 and string2.

  
  

  o strncat (string1, string2, count)

  ✓ Concatenates no more than count characters of string2 to string1.
• ▪ COMPARES

  
  

  o strcmp (string1, string2) / strcoll (string1, string2)

  ✓ Compares string1 and string2. Returns:

  • < 0 if string1 is less than string2.

  • 0 if string1 is equal to string2.

  • 0 if string1 is greater than string2.

  
  

  o stricmp (string1, string2) / strcmpi (string1, string2)

  ✓ Compares ignoring cases.

  
  

  o strncmp (string1, string2, count) / strnicmp (string1, string2, count)

  ✓ Compares no more than count characters, ignoring cases
• ▪ ERROR

  
  

  o _strerror(string)

  ✓ Displays custom error message followed by the most recent program error.

  
  

  o strerror(number)

  ✓ Returns a pointer to the error message associated with an error number.
• ▪ CASE

  
  

  o strlwr (string)

  ✓ Converts the string to lowercase.

  
  

  o strupr (string)

  ✓ Converts the string to uppercase.
• ▪ SET

  
  

  o strnset (string, c, count)

  ✓ Sets the first count characters in the string to the value of c.

  
  

  o strset (string, ch)

  ✓ Sets all characters in the string to the value of ch.
• ▪ MATCH

  
  

  o strcspn (string1, string2)

  ✓ Returns the index of the first character in string1 that matches any in string2.

  
  

  o strspn (string1, string2)

  ✓ Returns the index of the first character in string1 that does not match any in string2.

  
  

  o strpbrk (string1, string2)

  ✓ Returns a pointer to the first matching character.

  
  

  o strrchr (string, c)

  ✓ Returns a pointer to the last occurrence of c in the string.
• ▪ OTHERS

  
  

  o strchr (string, c)

  ✓ Returns substring from the first occurrence of c to the end.

  
  

  o strdup (string)

  ✓ Holds a duplicate of the string.

  
  

  o strlen (string)

  ✓ Returns the length of the string.

  
  

  o strrev (string)

  ✓ Reverses characters in the string
• ● MATHEMATICAL FUNCTIONS (math.h)

  
  

  ▪ abs (int num)

  o Returns the absolute value of num.

  
  

  ▪ ceil (double num)

  o Returns the smallest integer not less than num represented as a double.

  
  

  ▪ fabs (double num)

  o Returns the float absolute value of num.

  
  

  ▪ floor (double num)

  o Returns the largest integer not greater than num, represented as a double.

  
  

  ▪ fmod (double x, double y)

  o Returns the remainder of x/y.

  
  

  ▪ pow (double base, double exp)

  o Returns base raised to the power exp.

  ▪ pow10 (int n) o Returns 10 raised to the power n. ▪ sqrt (double num) o Returns the square root of num.
• ● CHARACTER FUNCTIONS (ctype.h)

  ▪ isalnum (int ch)

  o Returns non-zero if ch is a letter of the alphabet or a digit.

  ▪ isalpha (int ch)

  o Returns non-zero if ch is a letter of the alphabet; otherwise, zero.

  ▪ isdigit (int ch)

  o Returns non-zero if ch is a digit (0-9); otherwise, zero.

  ▪ islower (int ch)

  o Returns non-zero if ch is a lowercase letter (a-z); otherwise, zero.

  ▪ ispunct (int ch)

  o Returns non-zero if ch is a punctuation
• isalnum (int ch)

  o Returns non-zero if ch is a letter of the alphabet or a digit.