js-scavenger-hunt.md

Scavenger Hunt

Every item below refers to a specific function built into the JavaScript language. For each item, find:

1. The relevant page and section on MDN's official JavaScript documentation
2. At least one online resource (tutorial, etc.) other than Stack Overflow, w3cshools, or geekforgeeks explaining the function

Scavenger Items

1. Given two numbers, tell me how to get the remainder after dividing the former by the latter.

   I give you 10 and 3, you give me 1.

2. Given two arrays, tell me how get a new array that consists of all the elements in the first array followed by all the elements in the second array.

   I give you [10, 20, 30] and ['one', 'two', 'three'], you give me [10, 20, 40, 'one', 'two', 'three'].

3. Given two strings, tell me whether the second string appears anywhere in the first string.

   I give you 'one two three' and 'two', you give me true.

4. Given a string and a target length, tell me how to pad the end with a specific character (up to the target length).

   I give you 'yes' and 6 and tell you to pad with '-', you give me yes---.

5. Given an array and some condition, tell me how to get a new array consisting of all the elements from the original array that match the condition.

   I give you [12, 5, 8, 130, 44] and the condition that a number must be >= 10, you give me [12, 130, 44].

6. Tell me how to get the current year.

7. Given two strings (call them haystack and needle), tell me how to find the first index at which needle is found in haystack.

8. Given a string, tell me how to get the number of characters it contains.

9. Given a number, tell me how to get the largest integer less than or equal to that number.

   I give you 35.2 (or 35 or 35.9), you give me 35.

10. Given an array of numbers, tell me how to sort that array from smallest to largest.

    I give you [4, 19, 5, 1, 3], you give me [1, 3, 4, 5, 19].

11. Given a string, tell me how to get a copy of that string with all leading whitespace removed.

    I give you ' hello ', you give me 'hello '.

12. Given an array, tell me how to get the number of elements in the array.

    I give you ['one', 17, 'pie', 'orange juice'], you give me 4.

13. Given an array, tell me how to remove the last element from the array and save its value in a variable.

    I give you [5, 6, 22, -19]' and you remove -19, saving its value in a variable.

14. Given a dictionary (object), tell me how to get an array of all its keys.

    I give you { name: 'Jesse', age: 36 }, you give me ['name', 'age'].

15. Given two strings, tell me whether the second string appears at the end of the first string.

    I give you 'running' and 'ing', you give me true.

16. Given two or more numbers, tell me how to find the largest among them.

    I give you 8, -20, and 42, you give me 42.

17. Given a string, tell me how to get an all-uppercase copy of that string.

    I give you 'HeLLo FrIenDs', you give me 'HELLO FRIENDS'.

18. Given an array and a condition, tell me whether all elements in the array meet that condition.

    I give you [3, 7, 9, 11] and the condition "a number is odd", you give me true.

19. Tell me how to get the current month.

20. Given a string str, tell me how to find and replace every instance of some other string in str.

    I give you 'one two one three' and ask you to replace 'one' with 'potato', you give me back 'potato two potato three'.

21. Tell me how to get a random decimal number between 0 and 1.

22. Given an array and a value, tell me how to append that value to the array.

    I give you [19, -42, 56.4] and 'potato', you give me ['potato', 19, -42, 56.4].

23. Given a string, tell me how to get the character at a specific location (index) in the string.

24. Given a string containing the characters of an integer, tell me how to get an integer.

    I give you '1657', you give me 1657.

25. Given two or more numbers, tell me how to find the smallest among them.

    I give you 8, -20, and 42, you give me -20.

26. Given a string, tell me how to get a copy of that string with all trailing whitespace removed.

    I give you ' hello ', you give me ' hello'.

27. Given an array and some condition, tell me how to get the first element that matches the condition.

    I give you [5, 12, 8, 130, 44] and the condition that a number must be >= 10, you give me 12.

28. Given a string, tell me how to get a copy of that string with all leading and trailing whitespace removed.

    I give you ' hello ', you give me 'hello'.

29. Given an array and a value, tell me how to get the first index at which that value is found.

    I give you ['woof', 17, -45, 'woof', 'oranges', 'hawk'] and the value 'hawk', you give me 4 (the index of 'hawk').

30. Given two strings, tell me whether the second string appears at the start of the first string.

    I give you 'alphabet' and 'alpha', you give me true.

31. Given a variable, tell me how to get that variable's type (number, string, etc.).

    I give you 5, you give me 'number'.

    I give you 'hello', you give me 'string'.

    I give you true, you give me 'boolean'.

32. Given an array and some condition, tell me how to get the index of the first element that matches the condition.

    I give you '['one', 'three', 'waffles', 'beep'] and the condition that the length of the element is > 4, you give me 2 (the index of 'waffles').

33. Given a string str and a number num, tell me how to create a new string that consists of num copies of str glued together.

    I give you 'bark' and 3, you give me 'barkbarkbark'.

34. Given a string and a separator string, tell me how to get an array of all the parts of the string between occurrences of the separator.

    I give you 'pie|potato|waffle' and '|', you give me ['pie', 'potato', 'waffle'].

35. Given an object, tell me how to get an array of all its values.

    I give you { name: 'Jesse', age: 36 }, you give me ['Jesse', 36].

36. Given an array and a value, tell me how to append that value to the array.

    I give you [19, -42, 56.4] and 'potato', you give me [19, -42, 56.4, 'potato'].

37. Given a string and an index, tell me how to get the string consisting of all the characters starting at that index.

    I give you 'arglebargle' and 5, you give me 'bargle'.

38. Tell me how to get the number of milliseconds since 12AM UTC, January 1st, 1970 (called Unix time).

39. Given an object and a string, tell me whether that string occurs as a key in the object.

    I give you { name: 'Jesse', age: 36 } and 'age', you give me true.

    I give you 'potato', you give me false.

40. Given a string, tell me how to get an all-lowercase copy of that string.

    I give you 'HeLLo FrIenDs', you give me 'hello friends'.

41. Given a number, tell me how to get a string containing that numbers.

    I give you 1675, you give me '1657'.

42. Given an array, tell me how to get a reversed copy of that array.

    I give you ['one', 'two', 'three'], you give me a new array that looks like ['three', 'two', 'one'].

43. Given a number, tell me how to get the smallest integer greater than or equal to that number.

    I give you 8.2 (or 8 or 8.9), you give me 9.

44. Given a string str, tell me how to find and replace the first instance of some other string in str.

    I give you 'one two one three' and ask you to replace 'one' with 'potato', you give me back 'potato two one three'.

45. Given a string and a target length, tell me how to pad the start with a specific character (up to the target length).

    I give you 'yes' and 6 and tell you to pad with '-', you give me ---yes.

46. Given string representing your birthday, tell me how to get the day of the week it fell on.

    I give you 'June 23, 1986', you give me a value that represents Monday.

47. Given an array, tell me how to remove the first element from the array and save its value in a variable.

    I give you [5, 6, 22, -19]' and you remove 5, saving its value in a variable.

48. Given an array and a condition, tell me whether there are any elements in the array that meet that condition.

    I give you [3, 2, 9, 11] and the condition "a number is even", you give me true.

49. Given two strings, tell me the first location (index) at which the second string appears in the first.

    I give you 'one two one two' and 'two', you give me 4.

50. Given an array and a value, tell me how to check whether the array contains that value (as an element).

    I give you ['woof', 17, -45, 'oranges', 'hawk'] and the value 'hawk', you give me true.

51. Given an array and an index, tell me how to get a new array consisting of all elements from the original array starting at that index.

    I give you ['one', 'two', 'three', 'four'] and 2, you give me ['three', 'four'].

52. Given two strings, tell me the last location (index) at which the second string appears in the first.

    I give you 'one two one two' and 'two', you give me 12.