Delphi in a Nutshell

Name

Write Procedure

Syntax

procedure Write(var F: File; var Value; ...);
procedure Write(Expr:Width:Precision; ...);
procedure Write(var F: TextFile; Expr:Width:Precision; ...);

Description

The Write procedure writes text or other values to a file. If you are writing to a binary file, you must supply a variable of the same type as the file’s base type. You can write multiple records by listing multiple variables as arguments to the Write procedure.

When writing to a TextFile, you can write strings, numbers, characters, and Boolean values. Each value can be followed by the Width and Precision expressions, separated by colons. Width and Precision can be any integer expressions. Width specifies the minimum size of the string representation of Expr, and Precision specifies the number of places after the decimal point of a floating-point number.

Write uses as many characters as it needs, so Width is just the suggested minimum width. If the number requires fewer than Width characters, Write pads the string on the left with blanks. If you do not supply a Width, Delphi uses 1 as the minimum width for integers and it prints floating-point numbers as 26 characters in the following form:

'-1.12345678901234567E+1234'

If Expr is a floating-point number, Write reduces the number of decimal places to fit the value into a string that uses at most Width characters. Write always uses at least one digit after the decimal place, though. You can also supply a Precision, which tells Write how many decimal ...