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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Iterating through an Array

Posted by Christopher Roy
Christopher Roy
Courses Plus Student 1,325 Points

for loops with temps

When the variables in an array do not change by a fixed numerical value (i.e. 100 -> 90 = -10, but 90 -> 99 = +9) how do you tell the counter in the for loop what to change by after the loop runs?

Additionally, I am getting an error message saying that it can not evaluate the console.log command.

Any help would be greatly appreciated, thank you!

script.js 
var temperatures = [100,90,99,80,70,65,30,10];
for (i = 100; i < temperatures.list; i += i) {
  console.log( temperatures[ i ] );
}
index.html 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript Loops</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

2 Answers

jacinator
jacinator
11,936 Points
jacinator
jacinator
11,936 Points

This code will pass the challenge. i is tracking the index in the list, not the value.

var temperatures = [100,90,99,80,70,65,30,10];
for (i = 0; i < temperatures.length; i++) {
  console.log( temperatures[ i ] );
};
Bryan Peters
Bryan Peters
11,996 Points
Bryan Peters
Bryan Peters
11,996 Points

Keep in mind that "i" in your code represents the position index within the array. So each time you should just increment it by 1 to visit every item in the array. if you increment it by 2 you would be skipping every-other element in the array. Your code has it starting at 100 and incrementing by i, so first it visits temperatures[100] which doesnt exist (there are only 8 items in the array, and you are attempting to get the item in the 100th position, hence the error.

You are also using temperatures.list instead of temperatures.length

So instead, start at position 0 and increment by 1, until you reach the length of the array.

for (i = 0; i < temperatures.length; i += 1) {
     console.log( temperatures[i] );
}
Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

changed from comment to answer