Ruby 集合 << 方法
**< < **是Ruby中一个内置的方法,它可以将一个元素添加到集合中。
语法 :s1.name << (element)
参数 :该函数接收一个要添加到集合中的元素。
返回值 :它向集合中添加一个元素。
例子 1 :
#Ruby program to illustrate the << method
#requires the set
require "set"
s1
= Set[2, 1]
#Prints s1
puts s1
#Enters 4 into it
s1
<< 4
#Prints s1
puts s1
#Enters 4 into it
#But set has already 4
s1
<< 4
#Prints s1
puts s1
输出:
Set: {2, 1}
Set: {2, 1, 4}
Set: {2, 1, 4}
例2 :
#Ruby program to illustrate the << method
#requires the set
require "set"
s1
= Set[]
#Prints s1
puts s1
#Enters 1 into it
s1
<< 1
#Enters 2 into it
s1
<< 2
#Prints s1
puts s1
输出:
Set: {}
Set: {1, 2}
参考资料 : https://devdocs.io/ruby~2.5/set#method-i-3C-3C