Translation Go Slice Cheats

This is a creation in Article, where the information may have evolved or changed.

This is a summary of the official Golang: slicetricks

Due to the introduction of the built-in append approach, container/vector many of the package's methods are removed and can be replaced by built-in append and copy methods.

The following is the implementation of the operation method of the stack vector, using slice to implement related operations.

Appendvector

1	Append (A, B ...)

Copy

1234	Make Len (a)) Copy (b, a) //If A is not empty, you can also use the following method Append ([]t (nil), a ...)

Cut

Cut off a piece of data

1	Append (A[:i], a[j:] ...)

Delete

Delete an element

123	Append (A[:i], a[i+1:] ...) //ora = a[:i+copy(a[i:], a[i+1:])]

Delete, but do not keep the original order

12	A[i] = a[len(a)-1] A = a[:len(a)-1]

Note : If the element is a pointer, or a struct containing a pointer field, the cut delete implementation may have a potential memory leak. The values of some elements may be referenced all the time without a being released, and the following code will solve the problem.

Cut

12345

Copy (a[i:], A[j:]) for Len Len Nil //or the zero value of T} A = a[:len(a)-j+i]

Delete

123	Copy (a[i:], a[i+1:]) a[Len(a)-1nil//or the zero value of Ta = a[:len( A)-1]

Delete, but do not keep the original order

123	A[i] = a[len(a)-1]a[len(a)-1nila = a[:len(a)-1]

Expand

Insert a section into the middle

1	Append Append (make ([]t, J), A[i:] ...) ...)

Extend

Insert a section to the tail

1	Append Make ([]t, J) ...)

Insert

1	Append Append ([]t{x}, A[i:] ...) ...)

Note : The second append will use its underlying storage to create a new slice, then copy it a[i:] to this slice and then copy the slice back s . The creation of new slice and the second copy can be avoided using the following methods:

Insert

123	Append (s, 0) Copy (S[i+1:], S[i:]) s[i] = X

Insertvector

1	Append Append (b, A[i:] ...) ...)

Pop

1	X, a = a[len(a)-1], a[:Len(a)-1]

Push

1	Append (A, X)

Shift

1	X, A: = a[0], a[1:]

Unshift

1	Append ([]t{x}, a ...)

Other tricks

Filter with no additional object assignments

This technique leverages the slice to share its underlying data storage and capacity.

123456

B: = a[: 0]forrange a {ifappend(b, x)}}

Reverse

Reverses the elements in the slice.

1234	for Len (a) /2 -1; I >= 0Len(a)-1-ia[i], A[opp] = A[opp], A[i]}

The following code is similar, except that two index variables are used

123	for Left, right: = 0Len(a)-1; Left < right; Left, right = left+1, right-1 {a[left], a[right] = A[right], A[left]}