Array 类说明
函数名称
说明
示例
&
数组与，返回两数组的交集
[1,2] & [2,3] » [2]
*
复制数组 n 次
[1,2]*2 » [1,2,1,2]
+
返回两数组的并集，但不排除重复元素
[1,2]+[2,3] » [1,2,2,3]
<<
追加元素，但不排除重复元素
[1,2]<<[2,3] » [1,2,2,3]
|
追加元素，但排除重复元素
1,2] | [2,3] » [1,2,3]
-
返回第一个数组与第二个数组不同的元
素
[1,2]-[2,3] » [1]
<=>
比较数组
[1,2]<=>[2,3] »flase
==
比较数组，若所有元素均相等时返回真
[1,2]==[2,1] »flase
assoc
从数组的每个元素中寻找指定对象
[[1,2],[3,4]].assoc(2) » [1,2]
at
找到数组的第 N 个元素
负数表示逆向查找
["a","b","c","d","e"].at(0) » "a" ["a","b","c","d","e"].at(-1) » "e"
clear
删除数组中的所有元素
["a","b","c","d","e"]. clear
collect collect！
用一个过程块对数组的每个元素进行处
理
["a","b","c","d"].collect {|x| x + "!" }
» ["a!", "b!", "c!", "d!"]
compact compact!
删除值为 nil 的元素后生成新数组并返 回它
["a",nil,"b",nil,"c",nil].compact
» ["a", "b", "c"]
delete
删除元素，如果元素重复，全部删除
a = [ "a", "b", "b", "b", "c" ]
a.delete("b")
puts a » ["a","c"]
delete_at
删除 pos
所指位置的元素并返回它。若
pos
超出数组范围则返回 nil
a = %w( ant bat cat dog )
a.delete_at(2) » "cat"
a » ["ant", "bat", "dog"]
a.delete_at(99) » nil
delete_if
根据条件删除
a = [ "a", "b", "c" ]
a.delete_if {|x| x >= "b" } » ["a"]
each
对数组的每个元素按值进行迭代操作
a = [ "a", "b", "c" ]
a.each {|x| print x, " -- " }
» "a -- b -- c --"
each_index
对数组的每个元素按索引进行迭代操作
a = [ "a", "b", "c" ]
a.each_index {|x| print x, " -- " }
» "0 -- 1 -- 2 --"
empty?
判断数组是否为空，为空则返回真
[].empty? » true
eql！
比较两数组是否相等
["a","b","c"].eql?(["a","b","c"]) » true
fill
填充数组
["a","b","c","d"].fill("x")
» ["x","x","x","x"] ["a","b","c","d"].fill("z", 2, 2)
» ["x", "x", "z", "z"]
first
返回数组的首元素。若没有首元素则返
回 nil
[ "q", "r", "s", "t" ].first » "q"
last
返回数组末尾的元素。若数组为空时，
返回 nil
["w","x","y","z"].last » "z"
include?
判断数组中是否包含元素
a = [ "a", "b", "c" ]
a.include?("b") » true a.include?("z") » false
index
返回数组中第一个==val
的元素的位置
a = [ "a", "b", "c" ]
a.index("b") » 1 a.index("z") » nil
indexes
以数组形式返回其索引值与各参数值相 等的元素
a = [ "a", "b", "c", "d", "e", "f", "g" ]
a.indexes(0, 2, 4) » ["a", "c", "e"]
a.indexes( 2, 4, 12) �� [ "c", "e", nil]
insert
在索引为 nth
的元素前面插入第 2 参数 以后的值
ary = %w(foo bar baz)
ary.insert 2,'a','b'
p ary » ["foo", "bar", "a", "b", "baz"]
join
将数组元素按一定的分隔符连接起来
[ "a", "b", "c" ].join » "abc"
[ "a", "b", "c" ].join("-") » "a-b-c"
length
size
返回数组长度。若数组为空则返回 0
[1,2,3].length » 3 [1,2,3].size » 3
nitems
返回非 nil 元素的个数
[ 1, nil, 3, nil, 5 ].nitems » 3
pop
删除末尾元素并返回它。若数组为空则 返回 nil
a = [ "a", "m", "z" ]
a.pop » "z"
p a » ["a", "m"]
push
添加新元素
["a","b"].push(['1','2'])
» ["a", "b", ["1", "2"]]
rassoc
遍历数组每个元素（元素必须是数组），
匹配索引为 1 的值是否与查找的字符相 等，返回第一个相等的元素
a = [[15,1], [25,2], [35,2]]
p a.rassoc(2) » [25, 2]
replace
替换数组元素
a = ["a","b"]
a.replace(["x","y","z"])
p a »["x", "y", "z"]
reverse reverse！
将所有元素以逆序重新���列生成新数组
并返回它
["a","b","c" ].reverse » ["c", "b", "a"]
rindex
返回最后一个值相等的元素的索引值
a = [ "a","b","b","b","c"]
a.rindex("b") » 3
shift
删除数组的首元素并返回它。剩余元素 依次提前。若数组为空返回 nil。
args = ["-m","-q","filename"]
args.shift » "-m"
args » ["-q", "filename"]
sort
sort!
从小到大排序
a = [ "d", "a", "e", "c", "b" ]
a.sort » ["a", "b", "c", "d", "e"]
uniq uniq！
删除数组中的重复元素后生成新数组并
返回它
a = [ "a", "a", "b", "b", "c" ]
a.uniq » ["a", "b", "c"]
unshift
在数组第一个元素前添加元素
a = [ "b", "c", "d" ]
a.unshift("a") » ["a", "b", "c", "d"]
to_s
将数组的所有元素连接成字符串
["a","e","i","o"].to_s » "aeio"
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2013-11-15 8:57:26 |
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