I have a friend who has an assignment on arrays and because I lack experience in Javascript and she just needs some real quick help understanding how to implement a Javascript loop to store data in an array which converts a letter grade to a number. Can someone just guide her in a general direction?
Update: She states that she doesn't understand how to make it prompt again after the first time while storing data. Can someone just write a translation for a C++ code for do {}?
Here's a more or less complete solution - but it doesn't output the results to the HTML page but outputs it with the alert boxes.
var done = false,
classes = [],
total_credits = 0,
avg = 0;
while(!done){
var class_name = prompt("Enter class name"),
letter_grade = prompt("Enter letter grade for "+class_name),
credit_hours = prompt("Enter credit hours for "+class_name),
number_grade = {"A":4,"B":3,"C":2,"D":1,"F":0}[letter_grade];
if(class_name && letter_grade && credit_hours){
classes.push({
class_name: class_name,
letter_grade: letter_grade,
number_grade: number_grade,
credit_hours: credit_hours
});
total_credits += parseInt(credit_hours,10);
avg += number_grade*credit_hours;
}else
done = true;
}
avg = avg/total_credits;
for(var i=0; i<classes.length; i++){
alert(classes[i].class_name + " | " +
classes[i].letter_grade + " | " +
classes[i].credit_hours);
}
alert("Total credits: " + total_credits);
alert("GPA: " + avg.toFixed(2));
Basically, she should use a while loop.
in (mostly) pseudocode:
more_entries = true;
while(more_entries)
{
response = prompt("Question for the user","");
if (response == null)
{
more_entries = false;
}
else
{
// store value somewhere
}
}
Of course, this needs to be expanded to multiple prompts.
