Question

function averageCalculator (numvalues) {

    for(i=0, i <= numvalues, i++>) {
    var score = prompt("input the score")
    result1 += score;

    }

    alert(result1 / 3);
}

this function is later triggered by a button with onclick="averageCalculator (2)

<input type="button" value="Click for the average" onclick="averageCalculator (2)">

any ideas why its not working? it should prompt you for 2 values and then alert you with the average. not sure whats wrong.

Answer 1

Your code has multiple issues. The for loop is not well-formatted and you need to terminate statements with a semi-colon. Also, you need to declare variables. And your loop will run numvalues+1 times which is why I removed the = in your loop. Also if you want to calculate an average you want to divide by numvalues.

function averageCalculator (numvalues) {
var result1 = 0;
for(let i=0; i < numvalues; i++) {    
    var score = prompt("input the score");   
    result1 += score;    
}
alert(result1 / numvalues);
}

numvalues represents the number of inputs you want to calculate average for.

On top of the invalid syntax you will run into a common "problem" with javascript here. The inputs are treated as strings and instead of being added they will be concatenated. Providing 2 and 2 as scores will result in 11. 2 concatenated with 2 = 22 / 2 = 11. You need to cast the value to a number explicitly before adding them together:

function averageCalculator (numvalues) {
var result1 = 0;
for(i=0; i < numvalues; i++) {    
    var score = prompt("input the score");   
    result1 += Number(score);    
}
alert(result1 / numvalues);
}

The code above will correctly return 2.