Values, Types & Operators Exercises

Problem One

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

• 17 number, 17
• 1 + 2 * 3 + 4 11, typeof nummber
• 800 / 80 / 8 1.25 , number
• 400 > 200 true, boolean
• 1 !== 1 false, boolean
• true || false true, if there one truth in || (or), it will be truth
• true && false false, boolean
• 20 % 6 2, number
• 'a' + 'b' ab, string

Problem Two

What will the following return?

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

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 | !B | !A | !A && !B | |-------|-------|--------|--------| | true | true | false | false | False | false | true | false | true | false | true | false | true | false | false | false | false | true | true | True

Problem Five

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

| A | B | A || B | !(A || B) | | True | True | True | False | | True | False | True | False | | False | True | 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

-> 2 + 6 + 1 -> 8 + 1 -> 9

Problem Seven

Write a step-by-step evaluation for the following expression (remember order of operations): 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"

Problem Ten

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

-> 12 + 2 -> 14