鲁比拉的“+=”(加等)意思是什么? [闭门]-allqahome-开发者的问答家园

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鲁比拉的“+=”(加等)意思是什么? [闭门]

原标题：What does "+=" (plus equals) mean in Ruby? [closed]

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Closed 11 years ago.

I m穿过Ruby tutorial,我可以掌握+=声明。谷歌无助,“Ruby +=”仅搜索“Ruby”。

Help is appreciated.

样本:

num = -10
num += -1 if num < 0
puts num   
#=> -11

最佳回答

num += -1

等于

num = num + -1

或,例如

num = num - 1

这反过来也可以作为书面形式。

num -= 1

问题回答

它一度做了两件事。

(1) It adds + 1 to num (2) Assigns back the result to num

其捷径:

num = num + 1

<代码>a += b仅为a = a + b的简短表格。你的发言:

num += -1 if num < 0

将简单地细分(通过添加<代码>-1<>>>/代码>)。从<条码>南中删除。如果已经是负面的(请num < 0)。

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