Array.GetLowerBound(Int32) Metoda
Definicja
Ważne
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Pobiera indeks pierwszego elementu określonego wymiaru w tablicy.
public:
int GetLowerBound(int dimension);public int GetLowerBound (int dimension);member this.GetLowerBound : int -> intPublic Function GetLowerBound (dimension As Integer) As IntegerParametry
- dimension
- Int32
Wymiar zerowy tablicy, którego indeks początkowy należy określić.
Zwraca
Indeks pierwszego elementu określonego wymiaru w tablicy.
Wyjątki
Przykłady
W poniższym przykładzie użyto GetLowerBound metod i GetUpperBound do wyświetlania granic tablicy jednowymiarowej i dwuwymiarowej oraz wyświetlania wartości ich elementów tablicy.
using namespace System;
void main()
{
// Create a one-dimensional integer array.
array<int>^ integers = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
// Get the upper and lower bound of the array.
int upper = integers->GetUpperBound(0);
int lower = integers->GetLowerBound(0);
Console::WriteLine("Elements from index {0} to {1}:", lower, upper);
// Iterate the array.
for (int ctr = lower; ctr <= upper; ctr++)
Console::Write("{0}{1}{2}", ctr == lower ? " " : "",
integers[ctr],
ctr < upper ? ", " : Environment::NewLine);
Console::WriteLine();
// Create a two-dimensional integer array.
array<int, 2>^ integers2d = { {2, 4}, {3, 9}, {4, 16}, {5, 25},
{6, 36}, {7, 49}, {8, 64}, {9, 81} };
// Get the number of dimensions.
int rank = integers2d->Rank;
Console::WriteLine("Number of dimensions: {0}", rank);
for (int ctr = 0; ctr < rank; ctr++)
Console::WriteLine(" Dimension {0}: from {1} to {2}",
ctr, integers2d->GetLowerBound(ctr),
integers2d->GetUpperBound(ctr));
// Iterate the 2-dimensional array and display its values.
Console::WriteLine(" Values of array elements:");
for (int outer = integers2d->GetLowerBound(0); outer <= integers2d->GetUpperBound(0);
outer++)
for (int inner = integers2d->GetLowerBound(1); inner <= integers2d->GetUpperBound(1);
inner++)
Console::WriteLine(" {3}{0}, {1}{4} = {2}", outer, inner,
integers2d->GetValue(outer, inner), "{", "}");
}
// The example displays the following output:
// Elements from index 0 to 9:
// 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
//
// Number of dimensions: 2
// Dimension 0: from 0 to 7
// Dimension 1: from 0 to 1
// Values of array elements:
// {0, 0} = 2
// {0, 1} = 4
// {1, 0} = 3
// {1, 1} = 9
// {2, 0} = 4
// {2, 1} = 16
// {3, 0} = 5
// {3, 1} = 25
// {4, 0} = 6
// {4, 1} = 36
// {5, 0} = 7
// {5, 1} = 49
// {6, 0} = 8
// {6, 1} = 64
// {7, 0} = 9
// {7, 1} = 81
using System;
public class Example
{
public static void Main()
{
// Create a one-dimensional integer array.
int[] integers = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
// Get the upper and lower bound of the array.
int upper = integers.GetUpperBound(0);
int lower = integers.GetLowerBound(0);
Console.WriteLine($"Elements from index {lower} to {upper}:");
// Iterate the array.
for (int ctr = lower; ctr <= upper; ctr++)
Console.Write($"{(ctr == lower ?" " : "")}{integers[ctr]}" +
$"{(ctr < upper ? ", " : Environment.NewLine)}");
Console.WriteLine();
// Create a two-dimensional integer array.
int[,] integers2d= { {2, 4}, {3, 9}, {4, 16}, {5, 25},
{6, 36}, {7, 49}, {8, 64}, {9, 81} };
// Get the number of dimensions.
int rank = integers2d.Rank;
Console.WriteLine($"Number of dimensions: {rank}");
for (int ctr = 0; ctr < rank; ctr++)
Console.WriteLine($" Dimension {ctr}: " +
$"from {integers2d.GetLowerBound(ctr)} to {integers2d.GetUpperBound(ctr)}");
// Iterate the 2-dimensional array and display its values.
Console.WriteLine(" Values of array elements:");
for (int outer = integers2d.GetLowerBound(0); outer <= integers2d.GetUpperBound(0);
outer++)
for (int inner = integers2d.GetLowerBound(1); inner <= integers2d.GetUpperBound(1);
inner++)
Console.WriteLine($" {'\u007b'}{outer}, {inner}{'\u007d'} = " +
$"{integers2d.GetValue(outer, inner)}");
}
}
// The example displays the following output:
// Elements from index 0 to 9:
// 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
//
// Number of dimensions: 2
// Dimension 0: from 0 to 7
// Dimension 1: from 0 to 1
// Values of array elements:
// {0, 0} = 2
// {0, 1} = 4
// {1, 0} = 3
// {1, 1} = 9
// {2, 0} = 4
// {2, 1} = 16
// {3, 0} = 5
// {3, 1} = 25
// {4, 0} = 6
// {4, 1} = 36
// {5, 0} = 7
// {5, 1} = 49
// {6, 0} = 8
// {6, 1} = 64
// {7, 0} = 9
// {7, 1} = 81
open System
// Create a one-dimensional integer array.
let integers = [| 2..2..20 |]
// Get the upper and lower bound of the array.
let upper = integers.GetUpperBound 0
let lower = integers.GetLowerBound 0
printfn $"Elements from index {lower} to {upper}:"
// Iterate the array.
for i = lower to upper do
if i = lower then printf " "
printf $"{integers[i]}"
if i < upper then ", " else Environment.NewLine
|> printf "%s"
printfn ""
// Create a two-dimensional integer array.
let integers2d =
array2D [ [ 2; 4 ]; [ 3; 9 ]; [ 4; 16 ]; [ 5; 25 ]
[ 6; 36 ]; [ 7; 49 ]; [ 8; 64 ]; [ 9; 81 ] ]
// Get the number of dimensions.
let rank = integers2d.Rank
printfn $"Number of dimensions: {rank}"
for i = 0 to rank - 1 do
printfn $" Dimension {i}: from {integers2d.GetLowerBound i} to {integers2d.GetUpperBound i}"
// Iterate the 2-dimensional array and display its values.
printfn " Values of array elements:"
for outer = integers2d.GetLowerBound 0 to integers2d.GetUpperBound 0 do
for inner = integers2d.GetLowerBound 1 to integers2d.GetUpperBound 1 do
printfn $" {'\u007b'}{outer}, {inner}{'\u007d'} = {integers2d.GetValue(outer, inner)}"
// The example displays the following output:
// Elements from index 0 to 9:
// 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
//
// Number of dimensions: 2
// Dimension 0: from 0 to 7
// Dimension 1: from 0 to 1
// Values of array elements:
// {0, 0} = 2
// {0, 1} = 4
// {1, 0} = 3
// {1, 1} = 9
// {2, 0} = 4
// {2, 1} = 16
// {3, 0} = 5
// {3, 1} = 25
// {4, 0} = 6
// {4, 1} = 36
// {5, 0} = 7
// {5, 1} = 49
// {6, 0} = 8
// {6, 1} = 64
// {7, 0} = 9
// {7, 1} = 81
Public Module Example
Public Sub Main()
' Create a one-dimensional integer array.
Dim integers() As Integer = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 }
' Get the upper and lower bound of the array.
Dim upper As Integer = integers.GetUpperBound(0)
Dim lower As Integer = integers.GetLowerBound(0)
Console.WriteLine($"Elements from index {lower} to {upper}:")
' Iterate the array.
For ctr As Integer = lower To upper
Console.Write("{0}{1}{2}", If(ctr = lower, " ", ""),
integers(ctr),
If(ctr < upper, ", ", vbCrLf))
Next
Console.WriteLine()
' Create a two-dimensional integer array.
Dim integers2d(,) As Integer = {{2, 4}, {3, 9}, {4, 16}, {5, 25},
{6, 36}, {7, 49}, {8, 64}, {9, 81} }
' Get the number of dimensions.
Dim rank As Integer = integers2d.Rank
Console.WriteLine($"Number of dimensions: {rank}")
For ctr As Integer = 0 To rank - 1
Console.WriteLine($" Dimension {ctr}: " +
$"from {integers2d.GetLowerBound(ctr)} to {integers2d.GetUpperBound(ctr)}")
Next
' Iterate the 2-dimensional array and display its values.
Console.WriteLine(" Values of array elements:")
For outer = integers2d.GetLowerBound(0) To integers2d.GetUpperBound(0)
For inner = integers2d.GetLowerBound(1) To integers2d.GetUpperBound(1)
Console.WriteLine($" {ChrW(&h07b)}{outer}, {inner}{ChrW(&h007d)} = " +
$"{integers2d.GetValue(outer, inner)}")
Next
Next
End Sub
End Module
' The example displays the following output.
' Elements from index 0 to 9:
' 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
'
' Number of dimensions: 2
' Dimension 0: from 0 to 7
' Dimension 1: from 0 to 1
' Values of array elements:
' {0, 0} = 2
' {0, 1} = 4
' {1, 0} = 3
' {1, 1} = 9
' {2, 0} = 4
' {2, 1} = 16
' {3, 0} = 5
' {3, 1} = 25
' {4, 0} = 6
' {4, 1} = 36
' {5, 0} = 7
' {5, 1} = 49
' {6, 0} = 8
' {6, 1} = 64
' {7, 0} = 9
' {7, 1} = 81
Uwagi
GetLowerBound(0) zwraca indeks początkowy pierwszego wymiaru tablicy i GetLowerBound(Rank - 1) zwraca indeks początkowy ostatniego wymiaru tablicy.
Metoda GetLowerBound zawsze zwraca wartość wskazującą indeks dolnej granicy tablicy, nawet jeśli tablica jest pusta.
Należy pamiętać, że chociaż większość tablic na platformie .NET jest oparta na zerowej (czyli GetLowerBound metoda zwraca zero dla każdego wymiaru tablicy), platforma .NET obsługuje tablice, które nie są oparte na zera. Takie tablice można tworzyć za CreateInstance(Type, Int32[], Int32[]) pomocą metody , a także zwracać je z niezarządzanego kodu.
Ta metoda jest operacją O(1).