Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

FP 201 Unit 2 - Part 3

556 views

Published on

  • Be the first to comment

  • Be the first to like this

FP 201 Unit 2 - Part 3

  1. 1. FP 201 – ProgrammingFundamentalsOperators & Expressions
  2. 2. Learning outcomeBy the end of the course, students should be able to:Define the following operators: a. Arithmetic operator b. Assignment operator c. Increment and decrement operator d. Relational operator e. Logical operatorExplain operators’ precedenceExplain type conversionWrite expression using operatorUse expression in program
  3. 3. Operators Operator Action - subtraction (also unary minus) + addition * multiplication / division % modulus division -- decrement ++ increment && AND || OR ! NOT
  4. 4. OperatorsIs a symbol that instructs compiler to perform an operation or action.
  5. 5. Arithmetic Operators Perform four fundamental operations which are addition, subtraction, multiplication and division.Operator Description Example Result * Multiplication 2*8 16 / Division 8/2 4 + Addition 2+8 10 - Subtraction 8-2 6 () Parentheses. For grouping (8+2) 10 % Modulus. Divides two number and 4%3 1 returns just the remainder portion
  6. 6. Arithmetic Operatorsarithmetic expressions are evaluated with some rule called operator precedence. multiplications (*) and divisions (/) are evaluated first additions (+) and subtractions (-) are performed last.
  7. 7. Activity 1Write the resultant value of the following expressions. Expression Result 14-4 14+4 14* 4 14/4 14%4
  8. 8. ACTIVITY 2 Calculate the total marks for the given five subjects. Declare appropriate variables, assign values as given below: English = 85 Maths = 100 History = 75 Geography = 70 Art = 85  calculate the total marks  calculate the average
  9. 9. #include<iostream>using namespace std;int main(){ int english = 85, maths = 100, history = 75, geography = 70, art = 85; int sum=0; sum=english+maths+history+geography+art; cout<<"Sum is: "<<sum<<endl;; return 0;}
  10. 10. #include<iostream>using namespace std;int main(){ int english = 85, maths = 100, history = 75, geography = 70, art = 85; int sum=0, average=0; sum=english+maths+history+geography+art; average=sum/5; cout<<"Sum is: "<<sum<<endl; cout<<"Average is:"<<average<<endl; return 0;}
  11. 11. Assignment Operatorvariables are given a value through the use of assignment operator (=)general form: variable = expression;eg: int x, y; x = 2; y = 5*x; // y = 10 x = x + 4; // x = 6 y = y/2; // y = 5
  12. 12. Assignment OperatorThe value of an assignment can be used in another assignment.This is a chained assignment.Eg: m = (n = 66) + 9; // n = 66 and m = 75 x = y = 22; // x = 22 and y = 22
  13. 13. Compound Assignment Operators(+=), (-=), (*=), (/=), (%=)allow us to use assignment and an arithmetic operator together.general form is: variable operator= expression;
  14. 14. Compound Assignment OperatorsOperator Description Example Equivalent to += add and assign x += 3 x=x+3 -= subtract and assign x -= 5 x=x-5 *= multiply and assign x *= 4 x=x*4 /= divide and assign x /= 2 x=x/2 %= find reminder and assign x %= 9 x=x%9
  15. 15. In Class Exercise Given the following declaration and initial assignment: int i = 4, j = 21, k; float x = 94.55, y; char a = ‘z’, b = ‘t’, c =‘ ‘; Determine the value for the following assignments:  k=i*j y = x + i y = k = j  a = b =c  i += i
  16. 16. Increment & Decrement Operatorincrement operator (++) and decrement operator (--) increase or reduce by one the value stored in a variable.the following are equivalent in functionality. x++; x += 1; x = x + 1;characteristic of this operator: can be used both as a prefix and as a postfix. eg: a++ or ++a the results is different
  17. 17. PrefixWhen a prefix expression (++x or --x) is used as part of an expression, the value returned is the value calculated after the prefix operator is applied int x = 0; int y = 0; y = ++x; // result: y=1, x=1 x is incremented by 1 and the result is assigned to y
  18. 18. PostfixWhen a postfix expression (x++ or x--) is used as part of an expression, the value returned is the value calculated before the postfix operator is applied int x = 0; int y = 0; y = x++; // result: y=0, x=1 original value of x is stored, x is incremented, original value of x is assigned to y
  19. 19. Increment & Decrement Operatoreg: a = 5; // a = 5 b = a++; // b = a = 5, then a = 5+1 = 6 c = ++a; // a = 6+1 = 7, then c = a = 7
  20. 20. Relational Operator  Control statements use relation operators in order to compare two objects, which results in a value that is either true (1) or false (0).  There are six relational operators as follows:Operator Description Example Value < less than x<y 6<9 1 <= less than or equal to x <= y 12 <= 13 1 > greater than x>y 7 > 10 0 >= greater than or equal to x >= y 9 >= 5 1 == equal to x == y 7 ==5 0 != not equal to x != y 6 != 5 1
  21. 21. Logical OperatorOperator Description Example logical AND, conjunction. && Both sides must be true for the result to x > 2 && y == 3 be true logical OR, disjunction. || The result is true if either side or both x > 2 || x <= 9 sides are true. ! logical NOT, negation !(x>0)
  22. 22. Condition1 Condition2 && || true true true true true false false true false true false true false false false false
  23. 23. Logical Operatorusing these operators, we can form a Boolean Expression that can be either true or false.Boolean expressions evaluate to integer values.The value 0 means false and all non-zero value means true.There are also two literal constants used with bool variables: true and false.
  24. 24. In Class ExerciseWhat is the difference between x = 3 and x == 3?Given a = 2, b = 5, c = 7 determine the value for the following expressions either TRUE or FALSE: : 1. a < 2 && b > 5 2. c >= a 3. a < b || b > c 4. c != 10 5. a == 25
  25. 25. Operator Precedence Determines the order in which mathematical computations and operations are performed in an expression.
  26. 26. Operator Precedence
  27. 27. Operator PrecedenceGiven a=b = 5, c = 2; solve the following expression a+b*2/c–5 =5+5*2/2–5 = 5 + 10 / 2 – 5 =5+5–5 = 10 – 5 =5
  28. 28. In Class ExerciseGiven x = 10, y = 7, z = 2; solve the following expression x + 2y – z x / z – x * x + y x * y % z 5 ( x + y + z ) – x / z ++x*y – y*z
  29. 29. Type conversion/Type CastingIs the conversion of a value of one data type into another data type.Typecasting consist of two types:  Implicit conversion  Explicit conversion
  30. 30. Implicit conversionA value of data type with lower range is assigned to a variable of data type with higher rangeLower range to higher range
  31. 31. Example#include<iostream>using namespace std; OUTPUTvoid main() Result: 4.2555{ double x; // Size is 8 bytes int y=2; //Size is 4 bytes float z=2.2555f; x=y+z; //Implicit conversion cout<<"Result: "<<x;}
  32. 32. Explicit conversionA value of data type with higher range is assigned to a variable of data type with lower rangeHigher range to lower rangeExplicit conversion leads to data loss.
  33. 33. Example#include<iostream>using namespace std; OUTPUTvoid main() The total value is:300{ int total_value; double book1 = 300.46; total_value=(int)book1; // Explicit conversion cout<<"The total value is:"<<total_value;}
  34. 34. ExerciseWrite a program to declare a variable d of type double. Assign the value 102.5789 to d. Declare a float variable fl. Assign the value of d to fl by performing an explicit conversion and print the value on the screen.
  35. 35. Answer#include<iostream>using namespace std;void main() OUTPUT{ Value of the float variable fl = 102.579 double d=102.5789; float fl; fl=(float)d; // Explicit conversion cout<<"Value of the float variable fl = "<<fl;}
  36. 36. SummaryIn this presentation, you learnt the following:Operator is a symbol that instructs compiler to perform an operation or action.Typecasting is the conversion of data type of the value of a variable into another.There are two types of casting: implicit conversion and explicit conversion.
  37. 37. FP 201 – ProgrammingFundamentals with C++Input Output Statements
  38. 38. Learning outcomeBy the end of the course, students should be able to:Identify the syntax use for input and outputWrite program that use the input and output statements
  39. 39. Input/Output StatementsThe standard C++ library includes the header file iostream, where the standard input and output stream objects are declared. cout to output data to the screen and cin to input data from the keyboard.
  40. 40. Standard Outputstandard output: need to use cout, followed by the insertion operator (<<) eg: cout << "Hello World!"; // Outputs "Hello World!" on the screen cout << 1299; // Outputs the number 1299 on the screen cout << x; // Outputs the content of x on the screeninsertion operator (<<) may be used more than once in a single statement: cout << "Hi, " << "this is " << "a simple C++ statement";
  41. 41. Standard OutputNote that, cout does not add a line break.For example: cout << "Computer Programming "; cout << "is important for engineers."; will be output as: Computer Programming is important for engineers.
  42. 42. Standard OutputA line break can be added by inserting a n character or a using a endl manipulator. cout << "Computer Programming n"; cout << "is important for engineers."; cout << "Computer Programming " << endl; cout << "is important for engineers.";These two produce the following (same) output: Computer Programming is important for engineers.
  43. 43. Standard Input Handling the standard input is done by applying the overloaded operator of extraction (>>) on the cin stream Value can be input from the keyboard and assigned to a variable x as follows: cin >> x; and two variables can assigned as any of the follows: cin >> x; cin >> y; cin >> x >> y;
  44. 44. Code Example// Calculates the sum of two integers#include <iostream>using namespace std;int main() { int a, b, total; cout << "Enter two integers to be added: "; cin >> a >> b; total = a + b; cout << "The sum is " << total << endl; return 0; }
  45. 45. Code Example// Calculates the area of a triangle// given an input of the triangle base and height.#include <iostream>int main() { float base, height, area; std::cout << "Enter the base and height of the triangle: "; std::cin >> base >> height; area = 0.5*base*height; std::cout << "The area of the triangle is " << area << std::endl;}
  46. 46. Q&ADevelop a program that can calculate the total and average of four numbers that is input by user.
  47. 47. #include <iostream>using namespace std;int main() { int a, b, c, d, total, average; cout << "Enter four integers to be added: "; cin >> a >> b>>c>>d; total = a + b + c + d; average = total/4; cout << "The sum is " << total << endl; cout<< "The average is "<< average << endl; return 0; }
  48. 48. SummaryIn this presentation, you learnt the following:cout to output data to the screencin to input data from the keyboard.cout use insertion operator (<<)cin use overloaded operator of extraction (>>)

×