Current File : //proc/thread-self/root/opt/alt/ruby18/share/ri/1.8/system/Enumerable/reduce-i.yaml |
--- !ruby/object:RI::MethodDescription
aliases: []
block_params:
comment:
- !ruby/struct:SM::Flow::VERB
body: " enum.reduce(initial, sym) => obj\n enum.reduce(sym) => obj\n enum.reduce(initial) {| memo, obj | block } => obj\n enum.reduce {| memo, obj | block } => obj\n"
- !ruby/struct:SM::Flow::P
body: Combines all elements of <em>enum</em> by applying a binary operation, specified by a block or a symbol that names a method or operator.
- !ruby/struct:SM::Flow::P
body: If you specify a block, then for each element in <em>enum<i> the block is passed an accumulator value (<i>memo</em>) and the element. If you specify a symbol instead, then each element in the collection will be passed to the named method of <em>memo</em>. In either case, the result becomes the new value for <em>memo</em>. At the end of the iteration, the final value of <em>memo</em> is the return value fo the method.
- !ruby/struct:SM::Flow::P
body: If you do not explicitly specify an <em>initial</em> value for <em>memo</em>, then uses the first element of collection is used as the initial value of <em>memo</em>.
- !ruby/struct:SM::Flow::P
body: "Examples:"
- !ruby/struct:SM::Flow::VERB
body: " # Sum some numbers\n (5..10).reduce(:+) #=> 45\n # Same using a block and inject\n (5..10).inject {|sum, n| sum + n } #=> 45\n # Multiply some numbers\n (5..10).reduce(1, :*) #=> 151200\n # Same using a block\n (5..10).inject(1) {|product, n| product * n } #=> 151200\n # find the longest word\n longest = %w{ cat sheep bear }.inject do |memo,word|\n memo.length > word.length ? memo : word\n end\n longest #=> "sheep"\n"
full_name: Enumerable#reduce
is_singleton: false
name: reduce
params: |
enum.inject(initial, sym) => obj
enum.inject(sym) => obj
enum.inject(initial) {| memo, obj | block } => obj
enum.inject {| memo, obj | block } => obj
visibility: public