How do you comment out in Ruby?
Single-Line Comments The Ruby single-line comment begins with the # character and ends at the end of the line. Any characters from the # character to the end of the line are completely ignored by the Ruby interpreter.
How do you comment out a section of code in Ruby?
Single line comments in a Ruby script are defined with the ‘#’ character. For example, to add a single line comment to a simple script: # This is a comment line – it explains that the next line of code displays a welcome message print “Welcome to Ruby!”
What is used to start and end a comment?
The single line comment is //. Everything from the // to the end of the line is a comment. To mark an entire region as a comment, use /* to start the comment and */ to end the comment.
Why do we use begin and end in Ruby?
Every Ruby source file can run as the BEGIN blocks when the file is being loaded and runs the END blocks after the program has finished executing. The BEGIN and END statements are different from each other. Note :If an END statement is used in a loop Then it is executed more than once. …
What are magic comments in Ruby?
A magic comment changes the behavior of the Ruby interpreter in some way. For example: The frozen_string_literals comment will make your strings frozen by default. Another magic comment allows you to change the file’s encoding.
Which of the following would you begin a comment line with?
A comment starts with a slash asterisk /* and ends with a asterisk slash */ and can be anywhere in your program. Comments can span several lines within your C program. Comments are typically added directly above the related C source code.
What are some uses for comments?
Comments are text notes added to the program to provide explanatory information about the source code. They are used in a programming language to document the program and remind programmers of what tricky things they just did with the code and also helps the later generation for understanding and maintenance of code.
What does || mean in Ruby?
conditional assignment operator
||= is called a conditional assignment operator. It basically works as = but with the exception that if a variable has already been assigned it will do nothing. First example: x ||= 10. Second example: x = 20 x ||= 10. In the first example x is now equal to 10.
What is the syntax to open file in Ruby?
How to Write to a File in Ruby
- Open the file in write mode (“w” flag)
- Use the write method to add data to the file.
- If you didn’t use the block version, remember to close.
What is frozen string literal?
when you freeze a string literal(string object), you’re telling Ruby to not let any of your programs modify the string literal (object).
What does .freeze do in Ruby?
The freeze method in Ruby is used to ensure that an object cannot be modified. This method is a great way to create immutable objects. Any attempt to modify an object that has called the freeze method will result in the program throwing a runtime error.
How to write single line comments in Ruby?
1 !. 2 Single-Line Comments. The Ruby single-line comment begins with the # character and ends at the end of the line. 3 Multi-Line Comments. Though often forgotten by many Ruby programmers, Ruby does have multi-line comments. A multi-line comment begins with the =begin token and ends with the =end token.
How do you comment out a block of code in Ruby?
Let’s explore those! In Ruby, we do multiline comments with regular, single-line comments. Some people call these “block comments”. That’s exactly how to comment out a block of code in ruby. Modern code editors allow you to select a block of code & comment all of it using a keyboard shortcut, so there is no extra effort involved.
How are begin and end statements executed in Ruby?
If there is more than one BEGIN statement in a program, they are executed in the order If there is more than one END statement, they are executed in the reverse of the order. the first END one is executed last. An open curly brace always come after BEGIN and END keyword. BEGIN { Code . . .}
When do begin and end blocks run in Ruby?
Every Ruby source file can run as the BEGIN blocks when the file is being loaded and runs the END blocks after the program has finished executing. The BEGIN and END statements are different from each other. A program may contain multiple BEGIN and END blocks.