Ruby conditional branch processing

Conditional branch processing

Comparison operators (>,> =, <, <=, ==)

Comparison operator How to use Description

A> B Is A greater than B? = A> = B Is A more than B? <A <B A is less than B <= A <= B Is A less than or equal to B? == A == B Are A and B equal?

true, false

python

#Is 1 less than 20?
irb(main):001:0> 1 < 20
=> true

#Is 5 less than 5?
irb(main):002:0> 5 <= 5
=> true

#Is 1 greater than 20?
irb(main):003:0> 1 > 20
=> false

#Is 5 more than 5?
irb(main):004:0> 5 >= 5
=> true

#Is 2 x 5 equal to 10?
irb(main):005:0> 2 * 5 == 10
=> true

#Is 10 equal to 20?
irb(main):006:0> 10 == 20
=> false

Logical operator (!)

Operators that can check the authenticity of expressions and perform operations on boolean values are called logical operators. ! (Exclamation mark) is called the not operator and is used in the negative sense. ! =, which is a combination of! And =, returns true if the values are not equal in the opposite sense of ==.

python

#Isn't 2 x 3 6?
irb(main):001:0> 2 * 3 != 6
=> false
#Isn't 2 x 3 10?
irb(main):002:0> 2 * 3 != 10
=> true

if statement

The if statement can branch the process to be executed depending on whether the conditional expression is correct or incorrect, that is, true or false.

python

if conditional expression
processing
end

else (if statement)

Use else to process when the conditional expression is false in the if statement. Describe the processing when the condition is not met between else ~ end

python

if conditional expression
  #Conditional expression is true(true)Processing to be executed at
else
  #Conditional expression is false(false)Processing to be executed at
end

elsif (if statement)

elsif describes the processing when the conditional expression is false like else, but you can add the conditional expression like if when the condition is not satisfied.

python

if conditional expression 1
  #Conditional expression 1 is true(true)Processing to be executed at
elsif conditional expression 2
  #Conditional expression 1 is false(false)At that time
  #Conditional expression 2 is true(true)Processing to be executed at
else
  #Both conditional expression 1 and conditional expression 2 are false(false)Processing to be executed at
end

That is, the conditional branch of positive, negative, or 0 is as follows.

That's all from the scene!