Hướng dẫn dùng char.issymbol trong PHP

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Char.IsSymbol Method

• Reference

Definition

Indicates whether a Unicode character is categorized as a symbol character.

In this article

Overloads

Examples

The following code example demonstrates IsSymbol.

using namespace System;
int main()
{
   String^ str =  "non-symbolic characters";
   Console::WriteLine( Char::IsSymbol( '+' ) ); // Output: "True"
   Console::WriteLine( Char::IsSymbol( str, 8 ) ); // Output: "False"
}

using System;

public class IsSymbolSample {
    public static void Main() {
        string str = "non-symbolic characters";

        Console.WriteLine(Char.IsSymbol('+'));		// Output: "True"
        Console.WriteLine(Char.IsSymbol(str, 8));	// Output: "False"
    }
}

open System

let str = "non-symbolic characters"

printfn $"{Char.IsSymbol '+'}"      // Output: "True"
printfn $"{Char.IsSymbol(str, 8)}"  // Output: "False"

Module IsSymbolSample

    Sub Main()

        Dim str As String
        str = "non-symbolic characters"

        Console.WriteLine(Char.IsSymbol("+"c))      ' Output: "True"
        Console.WriteLine(Char.IsSymbol(str, 8))    ' Output: "False"

    End Sub

End Module

Remarks

Valid symbols are members of the following categories in UnicodeCategory: MathSymbol, CurrencySymbol, ModifierSymbol, and OtherSymbol.

Symbols in the Unicode standard are a loosely defined set of characters that include the following:

• Currency symbols.

• Letterlike symbols, which include a set of mathematical alphanumeric symbols as well as symbols such as ℅, №, and ™.

• Number forms, such as subscripts and superscripts.

• Mathematical operators and arrows.

• Geometric symbols.

• Technical symbols.

• Braille patterns.

• Dingbats.

IsSymbol(Char)

Indicates whether the specified Unicode character is categorized as a symbol character.

public:
 static bool IsSymbol(char c);

public static bool IsSymbol (char c);

static member IsSymbol : char -> bool

Public Shared Function IsSymbol (c As Char) As Boolean

Parameters

c Char

The Unicode character to evaluate.

Returns

true if c is a symbol character; otherwise, false.

Remarks

Valid symbols are members of the following categories in UnicodeCategory: MathSymbol, CurrencySymbol, ModifierSymbol, and OtherSymbol.

Symbols in the Unicode standard are a loosely defined set of characters that include the following:

• Currency symbols.

• Letterlike symbols, which include a set of mathematical alphanumeric symbols as well as symbols such as ℅, №, and ™.

• Number forms, such as subscripts and superscripts.

• Mathematical operators and arrows.

• Geometric symbols.

• Technical symbols.

• Braille patterns.

• Dingbats.

See also

• IsSymbol(Rune)
• Boolean

Applies to

IsSymbol(String, Int32)

Indicates whether the character at the specified position in a specified string is categorized as a symbol character.

public:
 static bool IsSymbol(System::String ^ s, int index);

public static bool IsSymbol (string s, int index);

static member IsSymbol : string * int -> bool

Public Shared Function IsSymbol (s As String, index As Integer) As Boolean

Parameters

index Int32

The position of the character to evaluate in s.

Returns

true if the character at position index in s is a symbol character; otherwise, false.

Exceptions

index is less than zero or greater than the last position in s.

Remarks

Character positions in a string are indexed starting from zero.

Valid symbols are members of the following categories in System.Globalization.UnicodeCategory: MathSymbol, CurrencySymbol, ModifierSymbol, and OtherSymbol.

Symbols in the Unicode standard are a loosely defined set of characters that include the following:

• Currency symbols.

• Letterlike symbols, which include a set of mathematical alphanumeric symbols as well as symbols such as ℅, №, and ™.

• Number forms, such as subscripts and superscripts.

• Mathematical operators and arrows.

• Geometric symbols.

• Technical symbols.

• Braille patterns.

• Dingbats.

See also

• Boolean
• String

Applies to