String Formatting

This was the tip of the week in the July 1, 2021 Ruby Weekly Newsletter.

We often need to format strings to appear a certain way. This week, we’ll cover several formatting and minor manipulation methods on Strings:

String#ljust and String#rjust both take an integer argument, and an optional padding argument. If the length of the string is smaller than the integer, they’ll return a new string of the length of the integer, padded with the padding argument repeated to fill the space, or spaces ( ) if no argument is passed. String#ljust padds on the right of the string, and String#rjust pads on the left:
```
  "This string needs a length of 35".ljust(35, "asdf")
  => "This string needs a length of 35asd"
	
  "This string is already longer than 35".ljust(35)
  => "This string is already longer than 35"
```
String#center behaves the same as String#ljust and String#rjust except it pads on both sides (with extra padding on the right in the case of an odd number of padding characters):
```
  "String".center(10)
  => "  String  "
```
String#delete_prefix takes a parameter of the prefix to delete, and does exactly what it claims. It is also faster than String#sub or String#gsub:
```
  "id_12345".delete_prefix("id_")
  => "12345"
```
If the prefix doesn’t exist, it will return the original String:
```
  "12345".delete_prefix("id_")
  => "12345"
```
String#delete_suffix works just like String#delete_prefix except it deletes from the end of the string:
```
  "uploaded_image_12.pdf".delete_suffix(".pdf")
  => "uploaded_image_12"
```