Question: 

In JavaScript, what's an array?

​

Answer: 

An ordered list that can contain a mix of different data types, 

including numbers, strings, and Booleans.

​

(It's like a column in a spreadsheet.)

*/

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// creating arrays

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let myArray = [2, 3, 5];

​

// accessing array elements

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console.log(myArray[0]); // 2 (the array element at index 0)

console.log(myArray[1]); // 3 (the array element at index 1)

console.log(myArray[2]); // 5 (the array element at index 2)

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// length of an array

console.log(myArray.length); // 3 (the array has three elements)

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// modifying array elements

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myArray[0] = 1; // note that myArray is now [1, 3, 5]

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// add a new element, 7, to the end of myArray

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// (can also do myArray[3] = 7;)

myArray.push(7);

console.log(myArray); // [1, 3, 5, 7]

​

/*

Exercise:

Create an xy-table of values for the equation y = x ** 2,

as a JavaScript array. Use x-values -2, -1, 0, 1, and 2.

*/

​

let xyTable = [[-2, 4], [-1, 1], [0, 0], [1, 1], [2, 4]];

console.log(xyTable[0]); // [-2, 4]

console.log(xyTable[0][1]); // 4

​

/*

In a JavaScript array, store the daily high temperatures from 

August 25-31, 2024 in the Denver area: 94, 88, 86, 92, 86, 87, 91

Source: https://www.weather.gov/wrh/Climate?wfo=bou

*/

​

let highTemps = [94, 88, 86, 92, 86, 87, 91];

​

/*

Exercise:

Compute the average of the temperatures in highTemps by "looping over

the array." Log the result to the console.

​

Remark:

If this were data for the whole month, a loop 

would be much more convenient than a hardcoded sum.

​

Note to self:

This is good practice with remembering that the length of the 

array and the last index in the array are not the same.

*/

​

/* Bonus exercise:

Previously, we wrote a computer program that predicted an item of food 

would expire in 1.698970004 weeks.

​

For fun, can you convert this value to the format 

"w weeks, d days, h hours, m minutes, s seconds"? 

For example, 9 days would be written as 

"1 week, 2 days, 0 hours, 0 minutes, 0 seconds".

​

Try to write a computer program that automates the repetitive steps

and outputs a formatted time. As always, try out your code to see if

it works!

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Hints (I should maybe put these in a separate file):

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1. Think about how you'd do the computation by hand. What's

the same in each step? What's different? 

​

2. The part that gets repeated over and over can go inside a loop.

​

3. Each step uses a different conversion factor. You can put the 

conversion factors in an array and loop over the array, so that

each step can use a different value.

*/

​

/*

Questions that we'll address once we learn a little more: 

1) What's a good way to avoid using such a long line of code

   when creating the formatted string? 

   Programming a loop of some sort? Or create an "object"?

2) Could we make some kind of reusable singular/plural adjuster?

*/

​