Concatenation

Ruby provides two ways to concatenate arrays, i.e., to join them without nesting (placing one array inside another). The concat method does what its name suggests. Note that it modifies the original array.

potpourri = [false, "Snuffles", nil]
potpourri.concat(["rick", 3]) #=> [false, "Snuffles", nil, "rick", 3]

# concat modifies the original array
potpourri #=> [false, "Snuffles", nil, "rick", 3]

# using concat with an empty array as an argument is pointless
potpourri.concat([]) #=> [false, "Snuffles", nil, "rick", 3]

Try running the code. (Click the run button.)

The second method for concatenation is the addition operator (+). The addition operator, however, does not modify the arrays to its left or right. One can reassign the variable for the left array to its concatenated value.

potpourri = [false, "Snuffles", nil]
potpourri + ["rick", 3] #=> [false, "Snuffles", nil, "rick", 3]

# + does not modify the array
potpourri #=> [false, "Snuffles", nil]

# variable reassignment
potpourri = potpourri + ["rick", 3]
potpourri #=> [false, "Snuffles", nil, "rick", 3]

Try running the code. (Click the run button.)