Ruby学习二 数组(2)
ruby and watir学习之_Array 类
http://www.cnblogs.com/zhangfei/archive/2010/07/28/1786927.html
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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]
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-
返回第一个数组与第二个数组不同的元
素
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[ 1,2]-[2,3]????? ? [ 1]
<= >
比较数组
[ 1,2]<=>[2,3]?? ? fl ase
==
比较数组，若所有元素均相等时返回真
[ 1,2]==[2,1]????? ? fl ase
assoc
从数组的每个元素中寻找指定对象
[[ 1,2],[3,4]].assoc(2)? ? [ 1,2]
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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!"]
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compact compact!
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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"]
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d elete
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删除元素，如果元素重复，全部删除
a = [ "a", "b", "b", "b", "c" ]
a.delete("b")
pu t s a?????? ? ["a","c"]
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d elete_at
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删除 p o s 所指位置的元素并返回它。若
p o s 超出数组范围则返回 nil
a = %w( ant bat cat dog )
a.delete_at(2)??? ? " c at"
a????????????????????????? ? [" ant", "bat", "dog"]
a.delete_at(99)??? ? n i l
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d elete_if
根据条件删除
a = [ "a", "b", "c" ]
a.delete_if {|x| x >= "b" }?? ? [ " a"]
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each
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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 --"
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each_index
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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??? ? t rue
eql ！
比较两数组是否相等
[ " a","b","c"].eql?(["a","b","c"]) ? t rue
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fill
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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"]
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fi rst
返回数组的首元素。若没有首元素则返
回 nil
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[ "q", "r", "s", "t" ].first????? ? "q "
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l ast
返回数组末尾的元素。若数组为空时，
返回 nil
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[" w " , " x " , " y " , " z"].last?????????? ? " z"
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i n clude?
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判断数组中是否包含元素
a = [ "a", "b", "c" ]
a.include?("b")? ? t rue a.include?("z")? ? f alse
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i nd ex
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返回数组中第一个==v a l 的元素的位置
a = [ "a", "b", "c" ]
a.index("b")? ? 1 a.index("z")?? ? n i l
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i nd exes
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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]
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i n sert
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在索引为 n t h 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???? ? [ " f oo" , "bar", "a", "b", "baz"]
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j o i n
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"
l ength
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
n it ems
返回非 nil 元素的个数
[ 1, nil, 3, nil, 5 ].nitems? ? 3
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p o p
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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"]
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pu s h
添加新元素
[ " a","b"].push(['1','2'])
? ["a", "b", ["1", "2"]]
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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
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a = [[15,1], [25,2], [35,2]]
p a.rassoc(2)????????????????? ? [ 25, 2]
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replace
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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排列生成新数组
并返回它
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[ " a","b","c" ].reverse? ? [ " c", "b", "a"]
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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
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shift
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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"]
un i q 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"]
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un s h i f t
在数组第一个元素前添加元素
a = [ "b", "c", "d" ]
a.unshift("a")????? ? [ " a " , "b", "c", "d"]
t o_ s
将数组的所有元素连接成字符串
[ " a","e","i","o"].to_s???????? ? " aeio"
