我试着:
somearray = ["some", "thing"]
anotherarray = ["another", "thing"]
somearray.push(anotherarray.flatten!)
我预期的
["some", "thing", "another", "thing"]
但有
["some", "thing", nil]
我试着:
somearray = ["some", "thing"]
anotherarray = ["another", "thing"]
somearray.push(anotherarray.flatten!)
我预期的
["some", "thing", "another", "thing"]
但有
["some", "thing", nil]
当前回答
这里有两种方法,注意在这个例子中,第一种方法分配一个新数组(转换为somearray = somearray + anotherarray)
somearray = ["some", "thing"]
anotherarray = ["another", "thing"]
somearray += anotherarray # => ["some", "thing", "another", "thing"]
somearray = ["some", "thing"]
somearray.concat anotherarray # => ["some", "thing", "another", "thing"]
其他回答
试试这个,它将结合你的数组删除重复
array1 = ["foo", "bar"]
array2 = ["foo1", "bar1"]
array3 = array1|array2
http://www.ruby-doc.org/core/classes/Array.html
进一步的文档请参阅“Set Union”
Somearray = ["some", "thing"]
Anotherarray = ["another", "thing"]
Somearray + anotherarray
["some", "thing"] + ["another", "thing"]
详细阐述@Pilcrow的答案,对于大型数组唯一合适的答案是concat(+),因为它速度快,并且在循环中操作时不会分配一个新对象来进行垃圾回收。
下面是基准:
require 'benchmark'
huge_ary_1 = Array.new(1_000_000) { rand(5_000_000..30_000_00) }
huge_ary_2 = Array.new(1_000_000) { rand(35_000_000..55_000_00) }
Benchmark.bm do |bm|
p '-------------------CONCAT ----------------'
bm.report { huge_ary_1.concat(huge_ary_2) }
p '------------------- PUSH ----------------'
bm.report { huge_ary_1.push(*huge_ary_2) }
end
结果:
user system total real
"-------------------CONCAT ----------------"
0.000000 0.000000 0.000000 ( 0.009388)
"------------------- PUSH ----------------"
example/array_concat_vs_push.rb:13:in `block (2 levels) in <main>': stack level too deep (SystemStackError)
正如你所看到的,当数组足够大时,使用push会抛出ERROR:堆栈级别太深(SystemStackError)。
只是另一种方法。
[somearray, anotherarray].flatten
=> ["some", "thing", "another", "thing"]