CPSC 101b Classroom Demonstrations: 26 February 2018
<html><head><title> Stan Eisenstat: work.html </title><script>
// Does Your Program Work?
var response = prompt ("Does your program work (Y or N)?");
if (response == "Y") {
alert ("Congratulations!");
} else {
response = prompt ("Have you been working more than 1-2 hours (Y or N)?");
if (response == "Y") {
alert ("Stop for now and see the instructor for help.");
} else {
alert ("Keep at it. You should be done soon.");
}
}
</script></head></html>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<html><head><title> Stan Eisenstat: robust.html </title><script>
// Does Your Program Work? (Robust Version)
var response= prompt ("Does your program work (Y or N)?");
if (response == "Y") {
alert ("Congratulations!");
} else if (response == "N") {
response = prompt ("Have you been working more than 1-2 hours (Y or N)?");
if (response == "Y") {
alert ("Stop for now and see the instructor or one of the TAs.");
} else if (response == "N") {
alert ("Keep at it. You should be done soon.");
} else {
alert ("You did not answer Y or N so I cannot help you.");
}
} else {
alert ("You did not answer Y or N so I cannot help you.");
}
</script></head></html>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<html><head><title> Stan Eisenstat: veryrobust.html </title><script>
// Does Your Program Work? (Very Robust Version)
var response = prompt ("Does your program work (Y or N)?");
if (response == "Y" || response == "y") {
alert ("Congratulations!");
} else if (response == "N" || response == "n") {
response = prompt ("Have you been working more than 1-2 hours (Y or N)?");
if (response == "Y" || response == "y") {
alert ("Stop for now and see the instructor or one of the TAs.");
} else if (response == "N" || response == "n") {
alert ("Keep at it. You should be done soon.");
} else {
alert ("You did not answer Y or N so I cannot help you.");
}
} else {
alert ("You did not answer Y or N so I cannot help you.");
}
</script></head></html>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<html><head><title> Stan Eisenstat: coins.html </title><script>
// Solve the three coins problem using a pan balance: Which of
// coins A, B, and C is lighter or heavier.
var answer = prompt ("A vs. B: L or E or H?");
if (answer == "L") { // A < B
answer = prompt ("B vs. C: L or E or H?");
if (answer == "L") { // B < C
document.write ("You lied to me! A < B < C");
} else if (answer == "E") { // B = C
document.write ("Coin A is light.");
} else { // B > C
document.write ("Coin B is heavy.");
}
} else if (answer == "E") { // A = B
answer = prompt ("B vs. C: L or E or H?");
if (answer == "L") { // B < C
document.write ("Coin C is heavy.");
} else if (answer == "E") { // B = C
document.write ("You lied to me! A = B = C");
} else { // B > C
document.write ("Coin C is light.");
}
} else { // A > B
answer = prompt ("B vs. C: L or E or H?");
if (answer == "L") { // B < C
document.write ("Coin B is light.");
} else if (answer == "E") { // B = C
document.write ("Coin A is heavy.");
} else { // B > C
document.write ("You lied to me! C < B < A");
}
}
</script></head></html>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<html><head><title> Stan Eisenstat: smallest1.html </title><script>
// Prompt for three values A, B, and C and print smallest s (decision tree)
var a, b, c, s
a = prompt ("Enter A:");
b = prompt ("Enter B:");
c = prompt ("Enter C:");
if (a > b) {
if (b > c) {
s = c;
} else {
s = b;
}
} else {
if (a > c) {
s = c;
} else {
s = a;
}
}
document.write (s + " is the smallest of " + a + ", " + b + ", and " + c);
</script></head></html>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<html><head><title> Stan Eisenstat: smallest2.html </title><script>
// Prompt for three values A, B, and C and print smallest (compact version)
var a, b, c, t;
a = prompt ("Enter A:");
b = prompt ("Enter B:");
c = prompt ("Enter C:");
if (a < b) {
t = a;
} else {
t = b;
}
if (c < t) {
t = c;
}
document.write (t + " is the smallest of " + a + ", " + b + ", and " + c);
</script></head></html>