Method: CSV::Table#initialize

Defined in:

lib/csv/table.rb

#initialize(array_of_rows, headers: nil) ⇒ Table

:call-seq:

CSV::Table.new(array_of_rows, headers = nil) -> csv_table

Returns a new CSV::Table object.

• Argument array_of_rows must be an Array of CSV::Row objects.

• Argument headers, if given, may be an Array of Strings.

---

Create an empty CSV::Table object:

table = CSV::Table.new([])
table # => #<CSV::Table mode:col_or_row row_count:1>

Create a non-empty CSV::Table object:

rows = [
  CSV::Row.new([], []),
  CSV::Row.new([], []),
  CSV::Row.new([], []),
]
table  = CSV::Table.new(rows)
table # => #<CSV::Table mode:col_or_row row_count:4>

---

If argument headers is an Array of Strings, those Strings become the table’s headers:

table = CSV::Table.new([], headers: ['Name', 'Age'])
table.headers # => ["Name", "Age"]

If argument headers is not given and the table has rows, the headers are taken from the first row:

rows = [
  CSV::Row.new(['Foo', 'Bar'], []),
  CSV::Row.new(['foo', 'bar'], []),
  CSV::Row.new(['FOO', 'BAR'], []),
]
table  = CSV::Table.new(rows)
table.headers # => ["Foo", "Bar"]

If argument headers is not given and the table is empty (has no rows), the headers are also empty:

table  = CSV::Table.new([])
table.headers # => []

---

Raises an exception if argument array_of_rows is not an Array object:

# Raises NoMethodError (undefined method `first' for :foo:Symbol):
CSV::Table.new(:foo)

Raises an exception if an element of array_of_rows is not a CSV::Table object:

# Raises NoMethodError (undefined method `headers' for :foo:Symbol):
CSV::Table.new([:foo])

# File 'lib/csv/table.rb', line 199

def initialize(array_of_rows, headers: nil)
  @table = array_of_rows
  @headers = headers
  unless @headers
    if @table.empty?
      @headers = []
    else
      @headers = @table.first.headers
    end
  end

  @mode  = :col_or_row
end