Ruby If Nil Then 0

Remember also that a ruby method returns nil by default.

Ruby if nil then 0.

Executes code if the conditional is true. Everything else in ruby is considered true in a boolean context. Memoirs of a software team leader read more. In the first form if no arguments are sent the new array will be empty.

For example a plus. In ruby on rails what s the difference actually. If 0 puts 123 end 123 this is saying. I m new to ruby and i was surprised when i found out that all objects are true apart from nil and false.

September 11 2010 4 minute read tags. If you ve ever coded in php then you ve certainly had to deal with null and the same goes for c java and pretty much every mainstream modern programming language. When a size and an optional default are sent an array is created with size copies of default take notice that all elements will reference the same object default. B is interpreted as a plus b where the plus.

Some languages consider the number 0 as a false value but that s not the case in ruby. Method in the object referred to by variable a is called with b as its argument. Then because conditional statements treat nil as false we can write. If the conditional is not true code specified in the else clause is executed.

Notice ruby uses elsif not else if nor elif. For each operator plus. Let s evaluate their usefulness and potential problems that they bring to the table. There is a corresponding form of abbreviated assignment operator.

The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter. Ruby of course isn t the only language that needs the concept of nothing far from it. If 0 is true then print 123. And even those speaking ruby quite fluently don t usually know the tiny little details.

Most operators are actually method calls. For many beginning rubyists especially those having experience in other programming languages such as java or c checking whether variable is nil may seem a little bit confusing. There are plenty of options available. An if expression s conditional is separated from code by the reserved word then a newline or a semicolon.

Returns a new array. Railsの拡張 nil のいずれかでtrueを返す.