CPCS 202 LAB 4 If Statement I Mona

CPCS 202 - LAB 4 If Statement I. Mona Alshehri

If Statement: Statement 1 The if operation can be stated in words like this: Statement 2 If test is TRUE, execute the if statements. Otherwise, (test is FALSE) bypassed to the next statement. if TRUE Test expression FALSE (zero) Statement 3 (non zero) if statements

If Statement Syntax: if (expression) statement An expression is any combination of variables, constants, or function calls that evaluate to a value. If expression is true, statement is executed; otherwise statement is skipped.

if statement format if (test expression) { if statement 1; if statement 2; . . if statement n; } Test expression must be enclosed within parentheses Each if statement must terminated by a semicolon ; Note: when you have more than one if statement, you must use curly braces {}.

if statement Examples Determine the output for each of the following program segments? Assume that x=2 and y=3 if(x<y) Output 1 { cout<<“x=“<<x<<“n”; x=2 cout<<“y=“<<y<<“n”; y=3 } if(x) Output 2 { cout<<“The value of x is non-zero. n”; The value of x is non-zero. } if((x<y) || (x-y<0)) { ++x; Output 3 --y; x=3 cout<<“x=“<<x<<“n”; y=2 cout<<“y=“<<y<<“n”; }

RELATIONAL OPERATORS A relational operator allows you to make comparisons in a program.

Test expression The test expression is a conditional test with a TRUE or FALSE result. It’s may contains one or more conditions. To test a single condition, you will use the relational Boolean operators: == , != , < , > , <= , >= To test multiple conditions, you must use logical Boolean operators: || , &&

Test expression Examples Write a test expression for the following: x equal y x == y x larger than 0 x>0 x not equal y and a less than b ((x != y) && (a < b)) Note: when you have more than one condition it’s better to use parentheses().

Truth Table for logical operators: &&, ||, !

Program 1 Write a program that will read a number from user and tests if it’s modules 2 is equal zero, writes a message ? Output Screen: Enter any number: The number is even Inputs: Number Outputs: Message Processing: If number % 2 == zero, write “The number is even”

Program 2 void main() { int no; cout <<"Enter any number : "; cin >>no; if(no%2==0) cout<<"The number is even"; }

if else statement Causes one of two alternative statements to execute depending on the condition is true. Its syntax is: if (condition) statement 1; else statement 2; The statement 1 will be executed if the expression is non zero Otherwise, statement 2 will be executed.

Program 2 Write a program that will read 2 numbers from user and Finding the minimum values? int x, y, min; cout << “Input three integers: “; cin >> x >> y; if (x < y) min = x; else min = y; cout << “The minimum value is “ << min << ‘n’;

Nested if statement A nested if statement is an if statement that is included within another if statement. Syntax if (expression 1) { if (expression 2) statement }

else if statement Syntax: If(expression 1) statement 1 else if (expression 2) statement 2. . . else if (expression. N) statement. N else last statement next statement

else if statement Example if (total >=90) grade = ‘A’; else if (total >= 80) grade = ‘B’; else if (total >= 70) grade = ‘C’; else if (total >= 60) grade = ‘D’; else grade = ‘E’; next statement

Program 3: Write a program that request the user’s language and then print a greeting in that language. Output: Engl. , Fren. , Ger. , Ital. , or Rus. ? (e, f, g, i, r): e Welcome Where the greeting will be: English="Welcome" France="Bon jour" Germany=“Guten" Italian=“Bon giorno" Russian="Dobre utre"; Other language=“Sorry, we don't speak your language";

Program 3 code: { char language; cout<< "Engl. , Fren. , Ger. , Ital. , or Rus. ? (e, f, g, i, r): "; cin>>language; if(language=='e') cout<<"Welcome"; else if(language=='f') cout<<"Bon jour"; else if(language=='g') cout<<"Guten"; else if(language=='i') cout<<"Bon giorno"; else if(language=='r') cout<<"Dobre utre"; else cout<<"Sorry, we don't speak your language"; getch(); }