用法:遍历循环
说明:
每执行一次语句块,就传递参数给 key-value 键值对。
如果 each_xxx 后不带任何参数,语句块,将返回一个 enumerator 枚举器
语法:
each do |key| ... end # 一维数组
each do |key, value| ... end # 二维数组
each {| key, value | block } → hsh
each_pair {| key, value | block } → hsh
each_key {| key | block } → hsh
each_value {| value | block } → hsh
each → an_enumerator
each_pair → an_enumerator
each_key → an_enumerator
each_value → an_enumerator
示例:
# 数组形式
j = [100, 200]
j.each do |value|
puts puts "#{value}"
end
#
# Hash形式
h = { "a" => 100, "b" => 200 }
h.each do |key, value|
puts puts "#{key} is #{value}"
end
结果:
100
200
a is 100
b is 200
示例:
h = { "a" => 100, "b" => 200 }
h.each {|key, value| puts "#{key} is #{value}" }
结果:
a is 100
b is 200
示例:
h = { "a" => 100, "b" => 200 }
h.each_key {|key| puts key }
结果:
a
b
示例:
h = { "a" => 100, "b" => 200 }
h.each {|key, value| puts "#{key} is #{value}" }
结果:
a is 100
b is 200
示例:
h = { "a" => 100, "b" => 200 }
h.each_value {|value| puts value }
结果:
100
200