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Handling null-terminated strings

Object Pascal’s extended syntax allows the Read, Readln, Str, and Val standard procedures to be applied to zero-based character arrays, and allows the Write, Writeln, Val, AssignFile, and Rename standard procedures to be applied to both zero-based character arrays and character pointers. In addition, the following functions are provided for handling null-terminated strings. For more information about null-terminated strings, see Working with null-terminated strings.

Function	Description
StrAlloc	Allocates a character buffer of a given size on the heap.
StrBufSize	Returns the size of a character buffer allocated using StrAlloc or StrNew.
StrCat	Concatenates two strings.
StrComp	Compares two strings.
StrCopy	Copies a string.
StrDispose	Disposes a character buffer allocated using StrAlloc or StrNew.
StrECopy	Copies a string and returns a pointer to the end of the string.
StrEnd	Returns a pointer to the end of a string.
StrFmt	Formats one or more values into a string.
StrIComp	Compares two strings without case sensitivity.
StrLCat	Concatenates two strings with a given maximum length of the resulting string.
StrLComp	Compares two strings for a given maximum length.
StrLCopy	Copies a string up to a given maximum length.
StrLen	Returns the length of a string.
StrLFmt	Formats one or more values into a string with a given maximum length.
StrLIComp	Compares two strings for a given maximum length without case sensitivity.
StrLower	Converts a string to lowercase.
StrMove	Moves a block of characters from one string to another.
StrNew	Allocates a string on the heap.
StrPCopy	Copies a Pascal string to a null-terminated string.
StrPLCopy	Copies a Pascal string to a null-terminated string with a given maximum length.
StrPos	Returns a pointer to the first occurrence of a given substring within a string.
StrRScan	Returns a pointer to the last occurrence of a given character within a string.
StrScan	Returns a pointer to the first occurrence of a given character within a string.
StrUpper	Converts a string to uppercase.

Standard string-handling functions have multibyte-enabled counterparts that also implement locale-specific ordering for characters. Names of multibyte functions start with Ansi-. For example, the multibyte version of StrPos is AnsiStrPos. Multibyte character support is operating-system dependent and based on the current locale.

Wide-character strings

The System unit provides three functions, WideCharToString, WideCharLenToString, and StringToWideChar, that can be used to convert null-terminated wide character strings to single- or double-byte long strings.

For more information about wide-character strings, see About extended character sets.

Topic groups

See also

Standard routines and I/O: Overview

译文

处理空结束串

Object Pascal扩展语法允许Read、Readln、Str和Val等标准过程适用于零基字符数组，允许Write、Writeln、Val、AssignFile和Rename等标准过程适用于零基字符数组和字符指针。另外，还提供下列函数来处理空结束串。关于空结束串的更多信息，见空结束串。

函数	描述
StrAlloc	在堆中分配给定尺寸的字符缓冲区
StrBufSize	返回用StrAlloc或StrNew分配的字符缓冲区的尺寸
StrCat	连接两个串
StrComp	比较两个串
StrCopy	复制一个串
StrDispose	释放用StrAlloc或StrNew分配的字符缓冲区
StrECopy	复制串并返回串尾指针
StrEnd	返回串尾指针
StrFmt	格式化一个或多个值到一个串中
StrIComp	比较两个串（大小写不敏感）
StrLCat	连接两个串（给定结果串的最大长度）
StrLComp	比较两个串（给定最大长度）
StrLCopy	复制串直到给定的最大长度
StrLen	返回串的长度
StrLFmt	格式化一个或多个值到一个串中（给定串的最大长度）
StrLIComp	比较两个串（给定最大长度且大小写不敏感）
StrLower	转换一个串到小写
StrMove	从一个串移动字符块到另一个串
StrNew	在堆中分配串
StrPCopy	复制一个Pascal串到一个空结束串
StrPLCopy	复制一个Pascal串到一个空结束串（给定最大长度）
StrPos	返回给定子串在串中第一次出现的位置指针
StrRScan	返回给定字符在串中最后一次出现的位置指针
StrScan	返回给定字符在串中第一次出现的位置指针
StrUpper	转换一个串到大写

标准的串处理函数还有相应支持多字节的函数，用于实现特定场所的字符命令。多字节函数的名称以Ansi-开始。例如，StrPos的多字节版本是AnsiStrPos。多字节字符的支持取决于操作系统，并且基于当前场所。

宽字符串

System单元提供了三个函数，WideCharToString、WideCharLenToString和StringToWideChar，它们用于转换空结束的宽字符串到单字节或双字节的长串。

有关宽字符串的更多信息，见关于扩展字符集。

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