VectorInt.Reverse Method

VectorInt Class

Overload List

#SignatureDescription
1function Reverse: TVecInt;Reverse vector elements.
└ indexed: function Reverse(const Index: Integer; const Len: Integer): TMtxVecInt;
2function Reverse(const Vec: TMtxVecInt): TVecInt;Reverse all Vec elements.
└ indexed: function Reverse(const Vec: TMtxVecInt; const VecIndex: Integer; const Index: Integer; const Len: Integer): TMtxVecInt;

Overload 1: function Reverse: TVecInt;

Reverse vector elements.

Result: stored in self (calling object), returns self for chaining

Remarks:

The method reverses vector elements by using the following equation:

V[k]=Vec[N−k],0≤k≤N,where N=Vec.Length−1\text{V}[k]=\text{Vec}[N-k],\quad 0\leq k \leq N, \quad \text{where } N=\text{Vec.Length}-1

This overload reverses all calling vector elements in-place.

Examples
var a: TVecInt;
begin
    CreateIt(a);
    try
        a.SetIt([1,2,3,4]);
        a.Reverse;   // a = [4,3,2,1]
    finally
        FreeIt(a);
    end;
end;
See Also: VectorInt.Rotate, VectorInt.Shift

Indexed: function Reverse(const Index: Integer; const Len: Integer): TMtxVecInt;

Reverses the calling object elements [Index]..[Index+Len-1].

#NameTypeDescription
1IndexIntegerstart index
2LenIntegerelement count

Result: stored in self (calling object), returns self for chaining

Remarks:

An exception is raised if array borders are overrun.

Overload 2: function Reverse(const Vec: TMtxVecInt): TVecInt;

Reverse all Vec elements.

#NameTypeDescription
1VecTMtxVecInt

Result: stored in self (calling object), returns self for chaining

Remarks:

Xtore the result in the calling vector elements. The TMtxVecBase.Length property of the calling vector is set to implicitly match Vec vector.

Examples
var a: TMtxInt;
begin
    CreateIt(a);
    try
        a.SetIt(2,2,[1,2,3,4]);
        a.Reverse(0,2);   // a = [2,1,3,4]
    finally
        FreeIt(a);
    end;
end;

Indexed: function Reverse(const Vec: TMtxVecInt; const VecIndex: Integer; const Index: Integer; const Len: Integer): TMtxVecInt;

Reverse vector elements.

#NameTypeDescription
1VecTMtxVecInt
2VecIndexInteger
3IndexIntegerstart index
4LenIntegerelement count

Result: stored in self (calling object), returns self for chaining

Remarks:

The method reverses Vec vector elements from [VecIndex].. [VecIndex+Len-1] and stores them in the calling vector from [Index]...[Index+Len-1] by using the following equation:

V[k]=Vec[N−k],0≤k≤N,where N=Vec.Length−1\text{V}[k]=\text{Vec}[N-k],\quad 0\leq k \leq N, \quad \text{where } N=\text{Vec.Length}-1

This overload reverses calling vector elements in-place.

Examples
var
    a: TVecInt;
begin
MtxVecInt.CreateIt(out a);
try
a.SetIt(new int[] {1,2,3,4});
a.Reverse;   // a = [4,3,2,1]
finally
MtxVecInt.FreeIt(ref a);
end;
end;
See Also: VectorInt.Rotate, VectorInt.Shift