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JavaScript JavaScript Array Iteration Methods Array Manipulation Practice filter()

Stephen Garcia
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.a{fill-rule:evenodd;}techdegree
Stephen Garcia
Python Development Techdegree Student 11,647 Points
Posted by Stephen Garcia
.a{fill-rule:evenodd;}techdegree
Stephen Garcia
Python Development Techdegree Student 11,647 Points

Using the filter method on the years array, return an array of only the years in the twentieth century

I'm getting back year.charAt is not a function. Just want to know why this is if the video before seems to use the same code to see if a name starts with S.

app.js 
const years = [1989, 2015, 2000, 1999, 2013, 1973, 2012];
let century20;

// century20 should be: [1989, 2000, 1999, 1973]
// Write your code below

century20 = years.filter(year => year.charAt(0) === 2);

2 Answers

Peter Vann
Peter Vann
36,427 Points
Peter Vann
Peter Vann
36,427 Points

Hi Stephen!

You are using the wrong filter test condition.

You want to return an array of dates that are the year 2000 or earlier.

This passes:

const years = [1989, 2015, 2000, 1999, 2013, 1973, 2012];
let century20;

// century20 should be: [1989, 2000, 1999, 1973]
// Write your code below

century20 = years.filter(year => {
    return year <= 2000;
});

Youkcan test it by pasting this code:

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Arrays</h2>

<p id="demo"></p>

<script>
const years = [1989, 2015, 2000, 1999, 2013, 1973, 2012];
let century20;

// century20 should be: [1989, 2000, 1999, 1973]
// Write your code below

century20 = years.filter(year => {
    return year <= 2000;
});

document.getElementById("demo").innerHTML = century20;
</script>

</body>
</html>

Here:

https://www.w3schools.com/js/tryit.asp?filename=tryjs_array

(Replace all the code, and run it and you'll get "1989, 2000, 1999, 1973" in the right pane.)

I hope that helps.

Stay safe and happy coding!