Single And Double Quoted String Notation

If you are building a string that involves interpolation and literal double quotes, then you'll have to do some escaping. Here is an example:

> feet, inches = [6, 4]
> puts "I am #{feet}'#{inches}\" tall"
I am 6'4" tall

Having to escape a single instance of a double quote isn't so bad. If you find yourself having to do it a bunch, Ruby has something for you. It is a string syntax feature called Percent Notation.

You can use percent notation to define double-quoted strings using Q:

> puts %Q[I am #{feet}'#{inches}" tall]
I am 6'4" tall

No need to escape the double quote here.

There is a single-quoted version as well using q:

> puts %q[I am #{feet}'#{inches}\" tall]
I am #{feet}'#{inches}\" tall

This is notably less useful than %Q. For that reason, %Q makes sense as a default and it makes up the percent notations unmodified behavior:

> puts %[I am #{feet}'#{inches}" tall]
I am 6'4" tall