* Problem 1: convert strings in snake_case to lowerCamelCase or UpperCamelCase.

*

* C programmers often use snake_case when naming functions or variables. In

* JavaScript, we use lowerCamelCase (first letter lower case) or UpperCamelCase

* (first letter Upper case) instead.

*

* You will write a function named toCamelCase() that accepts a string argument

* and converts it from snake_case to camelCase. The optional second argument

* determines whether or not to produce UpperCamelCase or not.

*

* The toCamelCase() function should work like this:

*

* toCamelCase('variable') returns 'variable'

* toCamelCase('variable_name') returns 'variableName'

* toCamelCase('variable_name', true) returns 'VariableName' ()

* toCamelCase('long_variable_name') returns 'longVariableName'

* toCamelCase('multiple___underscores') returns 'multipleUnderscores'

*

* @param {string} name - a string variable name to be converted

* @param {boolean} uppercase - (optional) whether to convert to UpperCamelCase

* defaults to `false`

* @return {string} - the converted camelCase version of the variable name

******************************************************************************/

function toCamelCase(name, uppercase) {

return name;

}

/*******************************************************************************

* Problem 2: create an HTML element with the given content.

*

* In HTML, a element is used to represent metadata about a web page. For

* example: who is tha page's author?

*

* If I wanted to indicate that a web page was written by Kim Lee, I would use

* the following tag:

*

*

*

* See the following for more details about the tag:

*

* - https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta

* - https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta/name

*

* Write a function named createMetaTag() which accepts both name and content values.

* It should use these values to produce a new tag string. For example:

*

* createMetaTag('description', 'Course notes for WEB222')

*

* should return the following string of HTML:

*

* ''

*

* Make sure you remove any leading or trailing whitespace from the name and content

* values before you use them.

*

* createMetaTag('description', ' Course notes for WEB222 ')

*

* should return the following string of HTML:

*

* ''

*

* Also, the double-quotes around name and content are optional if the value

* does NOT contain any of the following characters: space, tab, new line, line feed:

*

* ''

* ''

*

* When creating your string, only include double-quotes when necessary.

*

* @param {string} name - the value for the name attribute

* @param {string} content - the value for the content attribute

* @returns {string} - a properly formatted tag

******************************************************************************/

function createMetaTag(name, content) {}

/*******************************************************************************

* Problem 3: extract Date from date string

*

* A date string is expected to be formatted in one of the following formats:

*

* 1. YYYY-MM-DD

* 2. DD-MM-YYYY

*

* Here, the Year (4 digits) may be listed first or last. The Month (2 digits)

* will always be in the middle position, and the Day (2 digits) will either

* be last (when Year is first) or first (when Year is last).

*

* January 15, 2023 could therefore be represented in either of the following

* formats:

*

* 2023-01-15

* 15-01-2023

*

* Write a function, parseDateString() that accepts a date string of the formats

* specified above, and returns a new JavaScript Date Object, set to the correct

* day. In your solution, you will need to use use the following Date methods:

*

* - new Date() - creates a new Date Object

* - setFullYear() - sets the Date Object's year value

* - setMonth() - sets the Date Object's month value

* - setDate() - sets the Date Object's day value

*

* To help developers using your function, you are also asked to provide detailed

* error messages when the date string is formatted incorrectly. We will use the

* `throw` statement to throw a new Error object when a particular value is not

* what we expect, see:

* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/throw

*

* For example: parseDateString('01-01-01') should fail, because the year is

* not 4 digits.

*

* Similarly, parseDateString('2021-1-01') should fail because

* the day is not 2 digits, and parseDateString('2021-01-1') should fail because

* the month is not 2 digits.

*

* Also, a totally invalid date string should also cause an exception to be thrown,

* for example parseDateString(null) or parseDateString("this is totally wrong").

*

* @param {string} value - a date string

* @returns {Date}

******************************************************************************/

function parseDateString(value) {

if (!value)

throw new Error(

'invalid date string format. expected a YYYY-MM-DD or DD-MM-YYYY formatted string'

);

var dateParts = value.split('-');

var year, month, day;

if (dateParts[0].length !== 4) throw 'year value is wrong';

if (dateParts[1].length !== 2) throw 'month value is wrong';

if (dateParts[2].length !== 2) throw 'day value is wrong';

var date = new Date();

date.setFullYear(year);

date.setMonth(month - 1);

date.setDate(day);

return date;

}

/*******************************************************************************

* Problem 4: format a Date Object to use a given date string format.

*

* Building on your work in Problem 3 above, we want to be able to take a Date

* object, and format it into a string using one of the following 3 formats:

*

* 1. YYYY-MM-DD

* 2. DD-MM-YYYY

* 3. MM-DD-YYYY

*

* Meaning, Year (4 digits), Month (2 digits), Day (2 digits).

*

* Write a function, toDateString() that accepts a Date object and a date string

* format (e.g., "YYYY-MM-DD", "DD-MM-YYYY", or "MM-DD-YYYY"), and returns a date

* string formatted according to supplied format. Make sure your day and month

* values are padded with a leading '0' if necessary (e.g., 03 vs. 3).

*

* If something other than a valid Date Object is passed as the first argument,

* trying to call the Date methods will fail. You should use try/catch and

* throw a new Error object with an appropriate error message if this happens.

* See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch

*

* If the date string format is not one of the 3 listed above, throw a new Error

* with an appropriate error message explaining the problem.

*

* NOTE: it should be possible to use parseDateString() from the previous question

* and toDateString() to reverse each other. For example:

*

* toDateString(parseDateString('2021-01-29), "YYYY-MM-DD") should return '2021-01-29'

* toDateString(parseDateString('2021-01-29), "DD-MM-YYYY") should return '29-01-2021'

* toDateString(parseDateString('29-01-2021), "MM-DD-YYYY") should return '01-29-2021'

*

* @param {Date} value - a Date Object to be formatted

* @param {string} format - a format string, one of "YYYY-MM-DD", "DD-MM-YYYY", or "MM-DD-YYYY"

* @returns {string} - the formatted date string

******************************************************************************/

function toDateString(value, format) {

// Replace this comment with your code...

}

/*******************************************************************************

* Problem 5: parse a time duration

*

* Time duration is defined as a length of time expressed in hours, minutes, and

* seconds. An example, the duration from 9:15 AM to 10:45 AM is:

*

* Hours: 1

* Minutes: 30

* Seconds: 0

*

* A dataset includes thousands of time duration, stored as strings. However, over

* the years, different authors have used slightly different formats.

* All of the following are valid and need to be parsed:

*

* 1. "1:30:0"

* 2. "1h30m0s"

*

* In the first case, the values are separated by `:`. In the second, the values

* are followed by the unit (h, m, s).

*

* Valid Hour values are positive integers between 0 and 24.

*

* Valid Minute values are positive integers between 0 and 59.

*

* Valid Second values are positive integers between 0 and 59.

*

* If the input duration is invalid, return the value `null`.

*

* Parse the value and return a new string in the following form:

*

* "(hours, minutes, seconds)"

*

* @param {string} value - a time duration string in one of the given forms

* @returns {string|null} - a time duration formatted as "(hours, minutes, seconds)"

* or `null` if the duration isn't valid/recognized

*/

function normalizeDuration(value) {

// Replace this comment with your code...

}

/*******************************************************************************

* Problem 6: format any number of durations as a list in a string

*

* You are asked to format time durations (hour, min, sec) in a list using your

* normalizeDuration() function from problem 5.

*

* Where normalizeDuration() takes a single duration string, the formatDurations()

* function takes a list of any number of duration strings, parses them,

* filters out any invalid ones, and creates a list.

*

* For example: given the following durations, "1h13m2s" and "4:16:24",

* a new list would be created of the following form "((1, 13, 2), (4, 16, 24))".

*

* Notice how the list has been enclosed in an extra set of (...) braces, and each

* duration is separated by a comma and space.

*

* The formatDurations() function can take any number of arguments, but they must all

* be strings. If any of the values can't be parsed by normalizeDuration() (i.e., if

* it returns null), skip the value. For example:

*

* formatDurations("1h13m2s", "300:600:900", "4:16:24") should return

* "((1, 13, 2), (4, 16, 24))" and skip the invalid duration.

*

* @param {number} arguments - any number of string duration arguments can be passed

* @returns {string}

******************************************************************************/

function formatDurations(...values) {

// Replace this comment with your code...

}