Why I'm getting void value expression although I have assigned value

Question

I am new into ruby. I have the following code block:

a = 10

while a < 20 do
 puts "True"
a++

next unless a == 12
puts "This is not 12"
end


$end

However, I'm getting void value expression for a ==12.I have assigned 10 into it to begin with so I don't see why I'm getting void value.

Answer 1

replace a++ by a += 1 should work.

Ruby has no ++ operator. No increment operator (++) in Ruby?

Answer 2

Suppose

a = 2

The following are all equivalent, returning 5.

a++ 3
a + +3
a + +
3
a++

3

Therefore,

a++

next unless a == 12

is the same as

a + +next unless a == 12

This generates a "void value expression" exception because next unless a == 12 does not return a value (to be sent to the method :+).

The fix, of course, is to replace a++ with

a = a + 1

or its abbreviated form

a += 1