Ruby - Array#<< 和 Array#push 之间的区别
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Ruby - Difference between Array#<< and Array#push
提问by RavensKrag
From examining the documentation for Ruby 1.9.3, both Array#<< and Array#push were designed to implement appending an element to the end of the current array. However, there seem to be subtle differences between the two.
通过检查 Ruby 1.9.3 的文档，Array#<< 和 Array#push 都旨在实现将元素追加到当前数组的末尾。但是，两者之间似乎存在细微差别。
The one I have encountered is that the * operator can be used to append the contents of an entire other array to the current one, but only with #push.
我遇到的一个是 * 运算符可用于将整个其他数组的内容附加到当前数组，但只能使用 #push。
a = [1,2,3]
b = [4,5,6]
a.push *b
=> [1,2,3,4,5,6]
Attempting to use #<< instead gives various errors, depending on whether it's used with the dot operator and/or parentheses.
尝试使用 #<< 会产生各种错误，具体取决于它是否与点运算符和/或括号一起使用。
Why does #<< not work the same way #push does? Is one not actually an alias for the other?
为什么#<< 与#push 的工作方式不同？一个实际上不是另一个的别名吗？
回答by x1a4
They are very similar, but not identical.
它们非常相似，但并不完全相同。
<<accepts a single argument, and pushes it onto the end of the array.
<<接受单个参数，并将其推送到数组的末尾。
push, on the other hand, accepts one or more arguments, pushing them all onto the end.
push，另一方面，接受一个或多个参数，将它们全部推到最后。
The fact that <<only accepts a single object is why you're seeing the error.
<<仅接受单个对象的事实就是您看到错误的原因。
回答by David Weiser
The reason why <<does not work and pushdoes is that:
<<行不通的原因push是：
pushcan accept many arguments (which is what happens when you do*b).<<only accepts a single argument.
push可以接受许多参数（当你这样做时会发生什么*b）。<<只接受一个参数。
回答by Akshay Mohite
The main difference between Array#<< and Array#push is
Array#<< 和 Array#push 的主要区别是
Array#<< # can be used to insert only single element in the Array
Array#push # can be used to insert more than single element in the Array
Another significant difference is, In case of inserting single element,
另一个显着区别是，在插入单个元素的情况下，
Array#<< is faster than Array#push
Array#<< 比 Array#push 快
Benchmarkingcan help in finding out the performance of these two ways, find more here.
回答by Santhosh
Another important point to note here is that <<is also an operator. And it has a lower precedence than some operators like the ternary operator. This might lead to some unexpected results. eg:
这里要注意的另一个重点是这<<也是一个运算符。并且它的优先级低于一些运算符，例如三元运算符。这可能会导致一些意想不到的结果。例如：
arr1, arr2 = [], []
arr1.push true ? 1 : 0
arr1
# => [1]
arr2 << true ? 1 : 0
arr2
# => [true]
回答by Abhishek Singh
The pushmethod appends an item to the end of the array.It can have more than one argument.
<<is used to initialize array and can have only one argument , adds an element at the end of array if already initialized.
该push方法将一项附加到数组的末尾。它可以有多个参数。
<<用于初始化数组，只能有一个参数，如果已经初始化，则在数组末尾添加一个元素。
