CODEWITHSUNDEEP
javascript
Ktown
Ktown

Reputation: 109

Keep prompting in loop on false if condition

I am making a program where teachers input a student's name and grades corresponding to a certain number of assignments (the teacher specifies the assignment).

I want to make it so that it has to be a number value for the grades that are inputted. So, I've added this code:

for (var g = 1; g <= assignments; g++) {
     var grade = prompt("Please enter the student score for assignment" + g + ".");
     if(typeof grade === 'number' && Math.Round(grade) % 1 == 0) {
             return true;
         } 
     else{ 
             var grade = prompt("Please enter the student score for assignment" + g + ".");

         }

         var gradecolumn = document.createElement("td");
         var gradetext = document.createTextNode(grade);
         gradecolumn.appendChild(gradetext);
         rowtwo.appendChild(gradecolumn);
    }

I have this down... but I want to make it so it will continue to prompt until user inputs a valid data type.

Another problem I have is I want to add the grades together After they have been entered and calculate a cumulative grade to assign a letter grade on certain grading scale... I know I'm going to assign the letter grades via a multiconditional if/else if statement. But I'm not sure how to call the grades after they've been entered, and how to add them together so I can input that result into the multiconditional part.

Any help would be greatly appreciated.. Also, should I be using parseInt for any of this?

Upvotes: 1

Views: 477

Answers (2)

vladkras
vladkras

Reputation: 17227

var range = {"A": 100, "B": 75, "C": 50, "D": 30, "E": 20, "F": 10}, score = 0;
for (var g = 1; g <= 3; g++) {
    var grade = undefined, letter = '';
    while (!grade) {
        var grade = prompt("Please enter the student score for assignment" + g + ".");
        if (parseInt(grade)) {
            // accumulate score
            score += parseInt(grade);
        }
        // grade is not a number
        else grade = undefined;
    }
}
// check for mark
for (key in range) {
    if (score<range[key]) letter = key;
}

if (!letter) alert("score "+score+" is out of range!");
else {
    alert(letter); // now you have it
}

demo also updated: http://jsfiddle.net/vladkras/jNg2m/2/

Upvotes: 1

Seth
Seth

Reputation: 1373

Try this:

var g = 1;
var assignments = 5;
var done = false;
var grade, gradecolumn, gradetext;

while (!done)
{
    grade = prompt("Please enter the student score for assignment " + g + ".");
    if((grade+'').search(/^[0-9]{1,3}$/) > -1) 
    {
        gradecolumn = document.createElement("td");
        gradetext = document.createTextNode(grade);
         gradecolumn.appendChild(gradetext);
         rowtwo.appendChild(gradecolumn);

         // increment the counter
         g++;
         if (g > assignments)
         {
            done = true;
         }
    }
    else
    {
        alert('Please enter a valid score for assignment '+g+'.');
    }
}

Upvotes: 0

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