/values_types_operators_assignment

Primary LanguageJavaScript

Values, Types & Operators Exercises

Problem One

What are the types of the following expressions and what do they evaluate to, and why?

  • 17 ''' 17 (string because of the quotation marks) '''

  • 1 + 2 * 3 + 4 ''' 11 (2*3=6 then 1+6+4=11) '''

  • 800 / 80 / 8 ''' 1.25 '''

  • 400 > 200 ''' 400 is greater than 200 '''

  • 1 !== 1 ''' false, because 1 is 1 '''

  • true || false ''' true '''

  • true && false ''' false '''

  • 20 % 6 ''' 2 '''

  • 'a' + 'b' 'ab'

Problem Two

What will the following return?

  • typeof 4 number
  • typeof 'hello' string
  • typeof true booleans
  • 2 === 1 || 3 === 4 false

Problem Three

Create a truth table for the expression A || B.

For reference, here is a truth table for the expression A && B:

A B A && B
true true true
false true false
true false false
false false false

| A | B | A || B | |-------|-------|--------| | true | true | true | | false | true | true | | true | false | true | | false | false | false |

Problem Four

Create a truth table for the expression !A && !B.

For reference, here is a truth table for the expression A && !B:

A B !B A && B
true true false false
false true false false
true false true true
false false true false
!A !B !A && !B
false false false
true false false
false true false
true true true

Problem Five

Create a truth table for the expression !(A || B).

| A | B | !(A || B) | |-------|-------|-----------| | true | true | false | | false | true | true | | true | false | true | | false | false | true |

Problem Six

Write a step-by-step evaluation for the following expression (remember order of operations): 2 + 3 * 2 + 1. ''' 2 + 3 * 2 + 1 2 + 6 + 1 8 + 1 9 '''

For reference, here is a exp of a step-by-step evaluation:

1 + 2 + 3 + 4  
    3 + 3 + 4
        6 + 4
            10

Problem Seven

Write a step-by-step evaluation for the following expression (remember order of operations): 4 / 2 + 8 / 4. ''' 4 / 2 + 8 / 4 2 + 8 / 4 2 + 2 4 '''

Problem Eight

Write a step-by-step evaluation for the following expression: 'ca' + 'ter' + 'pi' + 'llar'. ''' 'ca' + 'ter' + 'pi' + 'llar' 'cater' + 'pi' + 'llar' 'caterpi' + 'llar' 'caterpillar' '''

Problem Nine

Write a step-by-step evaluation for the following expression: 2 * 4 === 8 && 'car' + 'pool' === 'carpool'. ''' 2 * 4 === 8 && 'car' + 'pool' === 'carpool' 8 === 8 && 'car' + 'pool' === 'carpool' 8 === 8 && 'carpool' === 'carpool' true && true true '''

Problem Ten

Write a step-by-step evaluation for the following expression: '1' + '2' + '3' - '1'. ''' '1' + '2' + '3' - '1' '12'+ '3' - '1' '123' - '1' '122' '''