How to initialize a slice with both initial value and capacity?
php editor Baicao will introduce how to use both the initial value and capacity during slice initialization to improve the efficiency of the code. In PHP, a slice is a dynamic array that can grow or shrink dynamically as needed. Usually, when initializing a slice, we can specify an initial value, but we cannot directly specify the capacity. However, there is a trick to initialize a slice using both initial value and capacity, let’s take a look!
Question content
Part of the code is as follows:
1 2 3 4 |
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Slicefibbo
There is no reserved
function in c like vector
to reserve estimatedsize
for the slice to reduce the problem when expanding the capacity Copy time. So I can only assign estimatedsize to capacity at initialization time. But neither of the following is legal.
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Is there any solution to this problem? Or maybe it's clumsy code and the following is the only way?
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Solution
No, this is not possible. This is part of the go design philosophy that guides this design decision: "Don't hide complexity."
Your "clumsy" code is actually the preferred and idiomatic way of doing this in go, with one small change:
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The only change I made (besides the format) was to remove the type from the var
declaration, as that was completely redundant. in other words:
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As pointed out in the comments, if you don't make any other changes to the input, you can also use the built-in copy
to eliminate the for loop:
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