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JavaScript JavaScript Array Iteration Methods Array Manipulation Practice filter()

Stephen Garcia
seal-mask
.a{fill-rule:evenodd;}techdegree
Stephen Garcia
Data Analysis Techdegree Student 10,169 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

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!

Stephen Garcia
seal-mask
.a{fill-rule:evenodd;}techdegree
Stephen Garcia
Data Analysis Techdegree Student 10,169 Points

Thanks so much Peter Vann! I clearly read it wrong. But if I were looking for every year starting with a 2 would it have worked properly?