1. Control Statement
tsenghy

2. 3 Control structures Sequential
Selection (Alternative) ( if-then-else )
if (expr) stat-1; else stat-2;
switch(expr) { case expr-1: stat-1; break; … }
Repetition (Loop)
for loop
while loop
do while

3. If Statements if ( CONDITION_1 ) { DO_ACTION_A }
else if ( CONDITION_2 )
DO_ACTION_B
else
DO_SOMETHING_ELSE

4. Switch-case switch ( condition ) { case A: case B: DO_ACTION_1; break;
case C:
DO_ACTION_2;
case D:
DO_ACTION_3;
default:
DO_SOMETHING_ELSE; }

5. Example: GPA Calculator
// Example program
#include <iostream>
using namespace std;
int main() {
int grade = 'A';
int GPA;
if ( grade == 'A' )
GPA = 4;
else if ( grade == 'B' )
GPA = 3;
else if ( grade == 'C' )
GPA = 2;
else if ( grade == 'D' )
GPA = 1;
else
GPA = 0;
cout << "GPA=" << GPA; }

6. Example: GPA Calculator
// Example program
#include <iostream>
using namespace std;
int main() {
int grade = 'A';
int GPA;
switch ( grade )
case 'A':
GPA = 4;
break;
case 'B':
GPA = 3;
case 'C':
GPA = 2;
case 'D':
GPA = 1;
default:
GPA = 0; }
cout << "GPA=" << GPA;

7. for Loop vs. while Loop i=1; do for(i=1 ; i<= 9 ; i++) { {
/* Loop body */
i++;
} while ( i<= 9 );
for(i=1 ; i<= 9 ; i++) {
/* Loop body */ }
i=1;
for( ; i<= 9 ; ) {
/* Loop body */
i++; }
i=1;
while( i<= 9 ) {
/* Loop body */
i++; }

8. Flow of for/while Loop     ; while( ) { ; ; } for( ;  ; ) {}; 
Get a plate ;
while( ) { ; ; }  no
Space?
Yes 
Find the food you want 
Put it in your plate

9. Example: all you can eat
// Example program
#include <iostream>
using namespace std;
int main() {
int space;
for(space = 10; space > 0; space--)
cout << "space left: " << space << endl;
cout << "put some potatoes in your plate" << endl; }
cout << "check space: " << space << endl;

10. Example: all you can eat
// Example program
#include <iostream>
using namespace std;
int main() {
int space = 10;
while(space > 0)
cout << "space left: " << space << endl;
cout << "put some potatoes in your plate" << endl;
space--; }
cout << "check space: " << space << endl;