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String::Format Method

Replaces each format item in a specified string with the text equivalent of a corresponding object's value.

This member is overloaded. For complete information about this member, including syntax, usage, and examples, click a name in the overload list.

  NameDescription
Public method Static member Format(String, Object) Replaces one or more format items in a specified string with the string representation of a specified object.
Public method Static member Format(String, array<Object>) Replaces the format item in a specified string with the string representation of a corresponding object in a specified array.
Public method Static member Format(IFormatProvider, String, array<Object>) Replaces the format item in a specified string with the string representation of a corresponding object in a specified array. A specified parameter supplies culture-specific formatting information.
Public method Static member Format(String, Object, Object) Replaces the format items in a specified string with the string representation of two specified objects.
Public method Static member Format(String, Object, Object, Object) Replaces the format items in a specified string with the string representation of three specified objects.
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Each overload of the Format method uses the composite formatting feature to include zero-based indexed placeholders, called format items, in a composite format string. At run time, each format item is replaced with the string representation of the corresponding argument in a parameter list. If the value of the argument is nullptr, it is replaced with String::Empty. For example, the following call to the Format method includes a format string with three format items, {0}, {1}, and {2}, and an argument list with three items.

No code example is currently available or this language may not be supported.

A format item has the following syntax:

{index[,alignment][ : formatString] }

Brackets denote optional elements. The opening and closing brackets are required. A format item has the following elements:

index

The zero-based index of the argument whose string representation is to be included at this position in the string. If the argument is nullptr, an empty string is included at this position in the string.

alignment

A signed integer that indicates the total length of the field into which the argument is inserted and whether it is right-aligned (a positive integer) or left-aligned (a negative integer). If alignment is omitted, the string representation of the corresponding argument is inserted in a field with no leading or trailing spaces.

formatString

A format string that specifies the format of the corresponding argument's result string. If formatString is omitted, the corresponding argument's parameterless ToString method is called to produce its string representation. If formatString is present, the argument referenced by the format item must implement the IFormattable interface. Types that support format strings include the following:

NoteNote

To include a literal opening or closing brace in the format string, see the "Escaping Braces" section in the Composite Formatting article.

The following example illustrates how to use optional elements in format items to produce formatted output.

No code example is currently available or this language may not be supported.
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