Values, Types & Operators Exercises

Problem One

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

• 17 number
• 1 + 2 * 3 + 4 number
• 800 / 80 / 8 number
• 400 > 200 comparison operator
• 1 !== 1 comparison operator
• true || false logical operator
• true && false logical operator
• 20 % 6 modulo
• 'a' + 'b' string concatenation

Problem Two

What will the following return?

• typeof 4 number
• typeof 'hello' string
• typeof true boolean
• 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 | | A | B | A || B |
|-------|-------|--------| |-------|-------|--------|
| true | true | true | | true | true | true | | false | true | false | | false | true | true | | true | false | false | | true | false | true | | false | false | false | | 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 | | A | B | !A && !B | |-------|-------|--------|--------| |-------|-------|--------| | true | true | false | false | | true | true | false | | false | true | false | false | | false | true | false | | true | false | true | true | | true | false | false | | false | false | true | false | | false | false | true |

Problem Five

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

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

Problem Six

Write a step-by-step evaluation for the following expression (remember order of operations): 2 + 3 * 2 + 1. 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. 2+8/4 2+2 4

Problem Eight

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