Table of Contents
What does splat do in Ruby?
A parameter with the splat operator converts the arguments to an array within a method. The arguments are passed in the same order in which they are specified when a method is called.
Does Ruby have a spread operator?
In both Ruby and JavaScript, you can use splat/spread to build up a new array from existing arrays.
How do you add to an array in Ruby?
To add array elements:
- Create an array: writers = []
- Add some elements to the end of the array (Figure 4.8): writers << ‘Sedaris’ writers << ‘McEwan’ << ‘Diaz’ writers.push(‘Bank’) puts writers.inspect.
- Add an element to the beginning of the array (Figure 4.9): writers.unshift(‘Hodgman’) puts writers.inspect.
Can you splat a hash Ruby?
Ruby 2.0 introduced keyword arguments, and ** acts like * , but for keyword arguments. It returns a Hash with key / value pairs. This answers the question perfectly, but I had a minor addendum. Just as the splat operator can be used on the array you pass, the double splat can be used on hashes.
What does double exclamation mark mean in Ruby?
In most programming languages, including Ruby, ! will return the opposite of the boolean value of the operand. So when you chain two exclamation marks together, it converts the value to a boolean.
Is Ruby a subset?
The subset?() is an inbuilt method in Ruby returns true if the set is a subset of the given set. Return Value: It returns self.
How do you get a substring in Ruby?
There is no substring method in Ruby. Instead we rely upon ranges and expressions. Substring ranges. With a range, we use periods in between 2 numbers—the first and last index of the substring.
What is a Ruby method?
A method in Ruby is a set of expressions that returns a value. Within a method, you can organize your code into subroutines which can be easily invoked from other areas of their program. A method name must start a letter or a character with the eight-bit set.
What does it mean when a method ends with in Ruby?
By convention, methods ending in ! have some sort of side-effect or other issue that the method author is trying to draw attention to. Examples are methods that do in-place changes, or might throw an exception, or proceed with an action despite warnings.