Ruby combining an array into one string

Here's my solution:

@arr = ['<p>Hello World</p>', '<p>This is a test</p>']
@arr.reduce(:+)
=> <p>Hello World</p><p>This is a test</p>

Use the Array#join method (the argument to join is what to insert between the strings - in this case a space):

@arr.join(" ")

While a bit more cryptic than join, you can also multiply the array by a string.

@arr * " "