Integer and Float number types in Ruby - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an Integer in Ruby?

An Integer is a whole number without a decimal point, like 5 or -10.

beginner

What is a Float in Ruby?

A Float is a number with a decimal point, like 3.14 or -0.5.

beginner

How do you write a negative Float number in Ruby?

You write a minus sign before the number, like -2.75.

intermediate

What happens if you divide two Integers in Ruby using `/`?

Ruby returns an Integer result if the division is not exact. For example, 5 / 2 returns 2.

beginner

How can you check the type of a number in Ruby?

Use the `.class` method. For example, `5.class` returns Integer, and `3.14.class` returns Float.

Which of these is an Integer in Ruby?

A -0.5

B 3.14

C 7.0

D 42

42 is a whole number without a decimal point, so it is an Integer.

What type does Ruby assign to the number 6.0?

A String

B Integer

C Float

D Boolean

6.0 has a decimal point, so Ruby treats it as a Float.

What is the result type of 7 / 3 in Ruby?

A Boolean

B Integer

C String

D Float

Ruby returns an Integer (2) when dividing two Integers with `/`.

How do you find out if a number is an Integer or Float in Ruby?

A Use `.class` method

B Use `.type` method

C Use `.kind` method

D Use `.typeof` method

The `.class` method returns the type of the object in Ruby.

Which of these is NOT a valid Float in Ruby?

A 7

B 0.0

C -3.5

D 2.718

7 is an Integer, not a Float, because it has no decimal point.

Explain the difference between Integer and Float number types in Ruby.

Think about numbers with and without decimals.

How can you check the type of a number in Ruby and why is it useful?

Use a method that tells you the object's class.