Concatenate

Two or more strings can be combined into one. This is called concatenation. In Ruby we use the plus operator—we add strings together. This yields a new string.

We can use operators to append and duplicate strings. Most programs do not need complex concatenations, but they are sometimes helpful.

Concat example

To begin we concatenate 2 strings. We add 2 string variables, value1 and value2, along with the "/" literal. We display the result.

# Two string values.
value1 = "Ruby"
value2 = "Python"

# Concatenate the string values.
value3 = value1 + "/" + value2;

# Display the result.
puts value3
Ruby/Python

Multiplication

Suppose we want to duplicate a string 2 or more times. We may want to repeat a pattern or word. We can multiply a string in Ruby.

# Use multiplication to concatenate a string many times.
result = "ba" + "na" * 2
puts result

# Write the string 3 times.
puts (result + " ") * 3
banana
banana banana banana

Append

Ruby has a special syntax for string appends. It uses the shift operator. We can use this operator to combine two or more strings. Here we append twice to a single string.

value = "cat"
puts value

# Append this string (surrounded by spaces).
value << " in "
puts value

# Append another string.
value << "the hat"
puts value
cat
cat in
cat in the hat

We can use concatenation and append on string variables and string literals. Many Ruby programs will need to append or combine strings.