jschallenger

Elegant Solutions For jschallenger.com

Javascript Basics

This series of challenges covers the very basics of Javascript.

• Sum two numbers
• Get type of value
• Get nth character of string
• Remove first n characters of string
• Get last n characters of string
• Get first n characters of string
• Extract first half of string
• Basic JavaScript math operators
• Remove last n characters of string
• Multiplication, division, and comparison operators
• Comparison operators, strict equality
• Check if a number is even
• Check if a number is a whole number
• Check whether a string contains another string and concatenate
• Round a number to 2 decimal places
• Find next higher natural number that is divisble by y
• Insert character after every n characters (backwards)
• Split a number into its digits
• Find the correct word by incrementing letters in alphabet
• Clear up the chaos behind these strings
• Return the percentage of a number
• How many times does a character occur?
• Return the next higher prime number

Javascript Arrays

This series of challenges tests your knowledge about Javascript arrays.

• Get nth element of array
• Remove first n elements of an array
• Get last n elements of an array
• Get first n elements of an array
• Sort an array of strings alphabetically
• Sort an array of numbers in descending order
• Return the average of an array of numbers
• Return last n array elements
• Sum up all array elements with values greater than
• Remove a specific array element
• Count number of elements in JavaScript array
• Count number of negative values in array
• Check if all array elements are equal
• Create a range of numbers
• Return the longest string from an array of strings
• Define an array with conditional elements
• Merge an arbitrary number of arrays
• Sort array by object property
• Merge two arrays with duplicate values
• Group array of strings by first letter.
• Get every nth element of array

Javascript Dates

This series of challenges tests your knowledge about Javascript dates.

• Return the next nearest quarter hour of a date
• Check if two dates fall on the exact same day
• Check if two dates are equal
• Check if one date is earlier than another
• Add n days to an existing date
• Check if two dates are within 1 hour from each other
• Return the number of days between two dates
• Calculate difference between two dates in hours, minutes, and seconds
• Return the next nearest quarter hour of a date

Javascript Objects

This series of challenges tests your knowledge about Javascript objects.

• Accessing object properties two
• Accessing object properties one
• Accessing object properties three
• Check if property exists in object
• Check if property exists in object and is truthy
• Creating Javascript objects one
• Creating Javascript objects two
• Creating Javascript objects three
• Extract keys from Javascript object
• Sum object values
• Remove a property from an object
• Swap object keys and values
• Add property to each object in array
• Merge two objects with matching keys
• Multiply all object values by x
• Extracting information from objects
• Replace empty strings in object with null values
• Convert array to object with counter

Javascript Sets

This series of challenges covers the Javascript Set object.

• Check if value is present in Set
• Convert a Set to Array
• Get union of two sets
• Creating Javascript Sets
• Delete element from Set
• Add multiple elements to Set
• Get Intersection of two Javascript Sets

DOM selector methods

• Select the button element on the page
• Query descendent HTML elements
• Select multiple HTML elements
• Query and exclude HTML elements

Events and user interactions

• Execute function on button click
• Execute function when cursor moves onto element
• Cursor enters and leaves element
• Move element with mouse cursor
• Drop element into another element