Ruby If Nil Then 0

I m new to ruby and i was surprised when i found out that all objects are true apart from nil and false.

Ruby if nil then 0.

In the first form if no arguments are sent the new array will be empty. If 0 is true then print 123. Everything else in ruby is considered true in a boolean context. Even 0 is true.

Remember also that a ruby method returns nil by default. For each operator plus. Notice ruby uses elsif not else if nor elif. Memoirs of a software team leader read more.

For example a plus. Ruby supports a rich set of operators as you d expect from a modern language. The values false and nil are false and everything else are true. B is interpreted as a plus b where the plus.

Method in the object referred to by variable a is called with b as its argument. If the conditional is not true code specified in the else clause is executed. Railsの拡張 nil のいずれかでtrueを返す. In ruby on rails what s the difference actually.

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. The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter. 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. Returns a new array.

Let s evaluate their usefulness and potential problems that they bring to the table. There are plenty of options available. Ruby of course isn t the only language that needs the concept of nothing far from it. Then because conditional statements treat nil as false we can write.

And even those speaking ruby quite fluently don t usually know the tiny little details. Some languages consider the number 0 as a false value but that s not the case in ruby. 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. Executes code if the conditional is true.

September 11 2010 4 minute read tags. An if expression s conditional is separated from code by the reserved word then a newline or a semicolon.