What is F in Ruby?

|f| is variable that takes each instance from the group comma, it does not make any change until unless you use it in your do..end loop. For example, if you need to access an attribute value of a particular instance of comma, you can have f.attributename, other wise |f| makes no difference.

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 does || do in Ruby?

Ruby Logical Operators

Operator	Description
||	Called Logical OR Operator. If any of the two operands are non zero, then the condition becomes true.
!	Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true, then Logical NOT operator will make false.

Does Ruby have a for loop?

In Ruby, for loops are used to loop over a collection of elements. Unlike a while loop where if we’re not careful we can cause an infinite loop, for loops have a definite end since it’s looping over a finite number of elements.

Do statements in Ruby?

Ruby for Statement:

• Like while and until, the do is optional.
• The for loop is similar to using each but does not create a new variable scope.
• The result value of a for loop is the value iterated over unless break is used.
• The for loop is rarely used in modern ruby programs.

What does the string% 02d in printf mean?

For example, a (%02d) in a format string for printf is a placeholder for an integer variable that will be printed in decimal (%02d) and padded to at least two digits, with zeros if necessary.

What’s the format for padding a number in Ruby?

You can convert a decimal number and print it as hexadecimal. Using the %x format: Use this format for padding a number with as many 0’s as you want: %0 d

How do you format a string in Ruby?

Well, you may want to do things like have a leading zero even if the number is under 10 (example: 01, 02, 03…), or have some console output nicely formatted in columns. In other languages you can use the printf function to format strings, and if you have ever used C you are probably familiar with that.

When to use encoding and capacity in Ruby?

The string, encoding, and capacity arguments may all be used together: If object is a String object, returns object. Otherwise if object responds to :to_str, calls object.to_str and returns the result. Raises an exception unless object.to_str returns a String object.