Misa Misa - 6 months ago 8
Javascript Question

Javascript code getoption

Write a function getoption(m,i) which takes a parameter m, a string of
words seperated by comma ",", and an integer i≥-1 and returns the ith
word in m. If i=-1, then a random word is returned else the ith word
is returned. No error checking is required.

For example, getoption("hello,hi,why,ok",1) must return hello.

must return ok.

MAY return either hello, hi, who OR

Hint: You need to split the string m by character ",". This will
result in an array of words. Remember the first word will be index
0!!!! Now if i is greater than -1, return element i+1 since again the
starting index of the array is 0. If i=-1 then generated a random
number from 0 to array.length-1 and then return the word corresponding
to this number.

Hello, I have written the code below and I have a typeerror on line 6 and I don't know how to fix it. Can someone help?

function getoption(m, i) {
var num = m + Math.floor((m + 1) * Math.random());
var j = i.indexOf(num);

while (j != -1) {
num = m + Math.floor((m + 1) * Math.random());
j = i.indexOf(num);

return (num);

document.write(getoption("hello,hi,why,ok", -1))


To get a wanted result, I suggest to split the string into a word array with String#split() and store it in an appropriate variable.

Then I suggest to check if the index is equal -1 and get a new index with the length of the array and Math.random().

Now return the element with the index of the word array.

function getoption(words, index) {
    var wordArray = words.split(',');
    if (index === -1) {
        index = Math.floor(Math.random() * wordArray.length);
    return wordArray[index];

document.write(getoption("hello,hi,why,ok", -1))