// APS101, Winter 2009: Lecture 17 (Feb. 23)
//
// Assignment 2 has been posted. Please start on it early.
// You will have a tutorial on A2 next Tuesday (Mar. 3). 
// Also, there will be TA office hours for A2 (time and location TBA).
// Check the FAQ page for updates and answers to common questions. 
//
// Review: so far, we've looked at basic concepts of Object-Oriented programming.

/**
 * 4 basic types of statements:
 * 
 * 1. Variable declaration
 * int x;
 * JFrame j;
 * 
 * 2. Variable assignment
 * x = 45;
 * j = new JFrame();
 * 
 * 3. return
 * return 24.2;
 * return 34 + 23 / 2;
 * return j;
 * return "Monday";
 * 
 * 4. method calls
 * j.setVisible(true);
 * "hello".substring(0, 3)
 */ 

// now, on to more complex things...
// if-statements:
//
// if (boolean-expression) {
//   then-part;
// }

int i = 10, j = 20, max;
i
j
max
if (i < j) {
   max =j;
}

i = 30 
if (i < j) {
   max =j;
}

max

// if(boolean-expression) {
//   then-part;
// } else {
//    else-part;
// }


i = 10; j = 20; max = 0;
i
j
max
if (i < j) {
   max = j;
} else {
   max = i;
}
max


// if(boolean-expression) {
//   then-part;
// }
// } else if (another boolean-expression) {
//   else if-part;
// } else {
//    else-part;
// }


i=10; j=20; max=0;
i
j
max
if (i < j) {
   max = j;
} else if (i > j) {
   max = i;
} else {
   // you can leave it blank - means "do nothing"!
}
max

 
int numEnrolled = 0;
int maxEnrolled = 5;
// If there is room in the course, then enrol a student.
// enrol a student: numEnrolled++;
// there is room in the course: numEnrolled < maxEnrolled
// if(there is room in the course) {
//   enrol a student
// }
if(numEnrolled < maxEnrolled) {
    numEnrolled++;
  }
numEnrolled
if(numEnrolled < maxEnrolled) {
    numEnrolled++;
  }
numEnrolled
if(numEnrolled < maxEnrolled) {
    numEnrolled++;
  }
if(numEnrolled < maxEnrolled) {
    numEnrolled++;
  }
if(numEnrolled < maxEnrolled) {
    numEnrolled++;
  }
if(numEnrolled < maxEnrolled) {
    numEnrolled++;
  }
numEnrolled


System.out.println("test"); // displays "test" on the screen
//out is a static object in "System" class

if(numEnrolled < maxEnrolled) {
    numEnrolled++;
    System.out.println("You are enrolled.");
  }

if(numEnrolled < maxEnrolled) {
    numEnrolled++;
    System.out.println("You are enrolled.");
  } else {
    System.out.println("The course is full.");
  }

// what if maxEnrolled is 50, or say 10000000?
// we need to use a loop! for now we will use "while" loops
// next week, we'll look at "for" loops 
// while loops:
//
// while (boolean termination condition) {
//    do something;
// }
// (the loop will keep going while the termination condition is true;
// in other words, the loop will stop when the termination condition
// becomes false)

int numEnrolled = 20;
int maxEnrolled = 10;
while (numEnrolled < maxEnrolled){
    numEnrolled++;
    System.out.println("Enrolled. You are student no:" + numEnrolled);
}

numEnrolled = 0;
maxEnrolled = 10;
while (numEnrolled < maxEnrolled){
    numEnrolled++;
    System.out.println("Enrolled. You are student no:" + numEnrolled);
}


numEnrolled = 0;
maxEnrolled = 10;
while (numEnrolled < maxEnrolled){
    numEnrolled++;
    System.out.println("Enrolled. You are student no:" + numEnrolled);
    if (numEnrolled == maxEnrolled) {
       System.out.println("The course is full.");
   }
}