I'm trying to write a function to calculate the elements average in an array using the parameter (...rest)
Here what I've tried:
function average(...nums) {
let total = 0;
for (const num of nums) {
total += num;
}
return total / nums.length;
}
console.log(average(2, 6));
console.log(average(2, 3, 3, 5, 7, 10));
console.log(average(7, 1432, 12, 13, 100));
console.log(average());But the last test returns NaN and I don't know why.
Because you're trying to divide 0 (total) by 0 (nums.length where nums is []), which is NaN in JavaScript.
You can have a check at the top of your function that returns a default value (say, 0), if the list is empty:
function average(...nums) {
if (!nums.length) return 0;
let total = 0;
// rest
}
You are returning 0/0 (which is NaN) when you pass nothing in, as nums becomes an empty array. and its length becomes 0.
You should return nums.length ? total/nums.length : 0;
function average(...nums)
{
let total = 0;
for(const num of nums)
{
total +=num;
n= nums.length;
}
return total/n;
}
console.log(average(2, 6));
console.log(average(2, 3, 3, 5, 7, 10));
console.log(average(7, 1432, 12, 13, 100));
console.log(average());
Check it the argument which is an array exists, if not return 0 or some value stating that average cannot be calculated.
function average(...nums) {
if (!nums.length) {
return 'Cannot find average'
}
let total = 0;
for (const num of nums) {
total += num;
}
return total / nums.length;
}
console.log(average(2, 6));
console.log(average(2, 3, 3, 5, 7, 10));
console.log(average(7, 1432, 12, 13, 100));
console.log(average());
The answer what you have provided will return NAN. So to avoid this get the length of the array/set of data and then divide the total only if the length is greater then 0.
function average(...value) {
let total =0;
for(const argument of value) {
total += argument;
}
return value.length>0?total/value.length : total;
}
console.log(average(2, 6));
console.log(average(2, 3, 3, 5, 7, 10));
console.log(average(7, 1432, 12, 13, 100));
console.log(average());
function average(...inputs) {
let avg = 0;
let sum = 0;
for(const input of inputs){
sum += input;
}
avg = sum / inputs.length;
return avg;
}
console.log(average(2, 6));
console.log(average(2, 3, 3, 5, 7, 10));
console.log(average(7, 1432, 12, 13, 100));
console.log(average());
count for every item in the array?A bit verbose, but here is a solution:
function average(...nums) {
let total = 0;
if (nums.length === 0) {
return total;
}
for (const num of nums) {
total +=num;
}
return total / nums.length;
}
For best practices, the last return statement should however be saved in a variable just in case the value needs to be referenced or reused elsewhere.
function average(...nums) {
let total = 0;
if (nums.length === 0) {
return total;
}
for (const num of nums) {
total +=num;
}
let averageTotal = total / nums.length;
return averageTotal;
}
