Replaces zero or more format specifications with the appropriately formatted value of an object.
[Visual Basic] Overloads Public Shared Function Format( _ ByVal format As String, _ ByVal arg0 As Object, _ ByVal arg1 As Object, _ ByVal arg2 As Object, _ ByVal arg3 As Object _ ) As String [C#] public static string Format( string format, object arg0, object arg1, object arg2, object arg3 ); [C++] public: static String* Format( String* format, Object* arg0, Object* arg1, Object* arg2, Object* arg3 ); [JScript] public static function Format( format : String, arg0 : Object, arg1 : Object, arg2 : Object, arg3 : Object ) : String;
A copy of the string is returned after replacing any format specifications with the appropriately formatted value.
Exception Type | Condition |
---|---|
ArgumentNullException | If the string is null. |
FormatException | If the string is invalid. |
The Format method replaces zero or more format specifications with the appropriately formatted value of an object. The format specifications are embedded within a string and are of the form {N:FormatString}, where N is a zero-based number indicating the argument that is to be formatted and FormatString is a format string. If argN implements IFormattable then argN.Format (format, null) provides the formatting; otherwise argN.ToString() provides the formatting. If arg0, arg1, arg2, or arg3 is null then an empty string is used in its place.
To Pad With Spaces: It is possible to define a region within the string argument in which the formatted value can be left or right justified. The format specification has an optional integer field: {N[,M]:FormatString}. The magnitude of M indicates the minimum number of spaces for the region and the sign of M indicates whether the value should be left (negative values) or right (positive values) justified within the region.
ToString() is Used if the Format String is Omitted: The format string within a format specification is optional: {N[,M][:FormatString]}. When FormatString is omitted, the ToString() method of the argument specified by N is used to replace the format specification. If M is given, then the result of ToString() is padded with spaces as described above.
If the string assigned to format is "Thank you for your purchase of {0:####} copies of Better Basket Weaving." and arg0 is an Int16 with the value 123, then the return value will be:
"Thank you for your purchase of 123 copies of Better Basket Weaving." If the String assigned to format is "Brad's dog has {0, -8:G} fleas." and arg0 is an Int16 with the value 42, then the return value will be: "Brad's dog has 42 fleas."
String Class | String Members | System Namespace | String.Format Overload List | Object | IFormattable