Find value in an array

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生来不讨喜
生来不讨喜 2020-12-23 23:52

In Ruby, how can I find a value in an array?

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  •  小蘑菇
    小蘑菇 (楼主)
    2020-12-24 00:21

    Like this?

    a = [ "a", "b", "c", "d", "e" ]
    a[2] +  a[0] + a[1]    #=> "cab"
    a[6]                   #=> nil
    a[1, 2]                #=> [ "b", "c" ]
    a[1..3]                #=> [ "b", "c", "d" ]
    a[4..7]                #=> [ "e" ]
    a[6..10]               #=> nil
    a[-3, 3]               #=> [ "c", "d", "e" ]
    # special cases
    a[5]                   #=> nil
    a[5, 1]                #=> []
    a[5..10]               #=> []
    

    or like this?

    a = [ "a", "b", "c" ]
    a.index("b")   #=> 1
    a.index("z")   #=> nil
    

    See the manual.

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