我只是在学习 COBOL；我正在编写一个简单地回显用户输入的程序。我已将变量定义为：
User-Input PIC X(30).
后来当我接受用户输入，然后显示用户输入“加上一些额外的文本”时，它有一堆空格来填充 30 个字符。有没有一种标准的方法（比如 Ruby 的 str.strip！）来删除多余的空格？
问问题
30252 次
5 回答
6
人们希望有一种更优雅的方式来简单地修剪文本字符串，但这几乎是标准解决方案......修剪部分在 SHOW-TEXT 段落中完成。
*************************************
* TRIM A STRING... THE HARD WAY...
*************************************
IDENTIFICATION DIVISION.
PROGRAM-ID. TESTX.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 USER-INPUT PIC X(30).
01 I PIC S9(4) BINARY.
PROCEDURE DIVISION.
MOVE SPACES TO USER-INPUT
PERFORM SHOW-TEXT
MOVE ' A B C' TO USER-INPUT
PERFORM SHOW-TEXT
MOVE 'USE ALL 30 CHARACTERS -------X' TO USER-INPUT
PERFORM SHOW-TEXT
GOBACK
.
SHOW-TEXT.
PERFORM VARYING I FROM LENGTH OF USER-INPUT BY -1
UNTIL I LESS THAN 1 OR USER-INPUT(I:1) NOT = ' '
END-PERFORM
IF I > ZERO
DISPLAY USER-INPUT(1:I) '@ OTHER STUFF'
ELSE
DISPLAY '@ OTHER STUFF'
END-IF
.
产生以下输出：
@ OTHER STUFF
A B C@ OTHER STUFF
USE ALL 30 CHARACTERS -------X@ OTHER STUFF
请注意，PERFORM VARYING 语句依赖于 UNTIL 子句的从左到右评估，以避免在 USER-INPUT 仅包含空格的情况下越界下标。
于 2010-01-12T17:22:22.987 回答
3
使用 OpenCOBOL 1.1 或更高版本。
Identification division.
Program-id. 'trimtest'.
*> Compile:
*> cobc -x -free -ffunctions-all TrimTest.cbl
*>
Data division.
Working-Storage Section.
1 myBigStr Pic X(32768) Value Spaces.
Procedure Division.
Display "Enter Something? " With no advancing.
Accept myBigStr.
Display "[" Trim(myBigStr) "]".
Goback.
修剪功能也有选项；领先或落后。cobc -h 了解更多信息。
于 2012-09-06T21:48:56.713 回答
1
如果您在 OpenVMS 上工作，这是一个解决方案：
01 WS-STRING-LENGTH PIC S9(04) COMP.
CALL "STR$TRIM" USING BY DESCRIPTOR user_output,
user_input,
BY REFERENCE WS-STRING-LENGTH.
于 2010-01-12T16:34:56.420 回答
0
更通用的解决方案：
01 length pic 99.
perform varying length from 1 by 1
until length > 30 or user-input[length] = space
end-perform.
if length > 30
display user-input 'plus some extra text'
else
display user-input[1:length] 'plus some extra text'
end-if.
未经测试，目前我手头没有编译器
于 2010-01-12T16:58:45.017 回答
0
您可以通过三种方式做到这一点。
- 使用 COBOL 函数来确定字符串的“长度”。这是几个功能的混合。这是我的首选方法，但需要声明额外的变量。
- 编写自己的函数来获取“长度”。
- 使用“终止”字符串的知识。您必须知道哪些关键字符表示字符串结尾，例如三个空格或低值字符。
此示例代码演示了所有三个。
IDENTIFICATION DIVISION.
PROGRAM-ID. TESTPROG.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 ONE-A PIC X(20) VALUE 'RALPH WIGGAM'.
01 ONE-A-TLY PIC 9(02) VALUE ZERO.
01 ONE-A-LEN PIC 9(02) VALUE ZERO.
01 ONE-B PIC X(20) VALUE 'LIKES LEARNDING'.
01 ONE-B-TLY PIC 9(02) VALUE ZERO.
01 ONE-B-LEN PIC 9(02) VALUE ZERO.
01 TWO-A PIC X(20) VALUE 'RALPH WIGGAM'.
01 TWO-A-LEN PIC 9(02) VALUE ZERO.
01 TWO-B PIC X(20) VALUE 'LIKES LEARNDING'.
01 TWO-B-LEN PIC 9(02) VALUE ZERO.
01 THREE-A PIC X(20) VALUE 'RALPH WIGGAM'.
01 THREE-B PIC X(20) VALUE 'LIKES LEARNDING'.
01 THREE-C PIC X(80) VALUE SPACES.
PROCEDURE DIVISION.
DISPLAY ' -- METHOD ONE -- '
INSPECT FUNCTION REVERSE(ONE-A)
TALLYING ONE-A-TLY FOR LEADING SPACES.
SUBTRACT ONE-A-TLY FROM LENGTH OF ONE-A GIVING ONE-A-LEN.
INSPECT FUNCTION REVERSE(ONE-B)
TALLYING ONE-B-TLY FOR LEADING SPACES.
SUBTRACT ONE-B-TLY FROM LENGTH OF ONE-A GIVING ONE-B-LEN.
DISPLAY ONE-A(1:ONE-A-LEN)
' ' ONE-B(1:ONE-B-LEN)
'.'.
DISPLAY ' -- METHOD TWO -- '
PERFORM VARYING TWO-A-LEN FROM LENGTH OF TWO-A BY -1
UNTIL TWO-A-LEN < 1 OR TWO-A(TWO-A-LEN:1) > SPACE
END-PERFORM.
PERFORM VARYING TWO-B-LEN FROM LENGTH OF TWO-B BY -1
UNTIL TWO-B-LEN < 1 OR TWO-B(TWO-B-LEN:1) > SPACE
END-PERFORM.
DISPLAY TWO-A(1:TWO-A-LEN)
' ' TWO-B(1:TWO-B-LEN)
'.'.
DISPLAY ' -- METHOD THREE, NAIVE -- '
* DELIMITING BY JUST ANY SPACES ISN'T GOOD ENOUGH.
STRING THREE-A DELIMITED BY SPACES
' ' DELIMITED BY SIZE
THREE-B DELIMITED BY SPACES
'.' DELIMITED BY SIZE
INTO THREE-C.
DISPLAY THREE-C.
DISPLAY ' -- METHOD THREE, OK -- '
STRING THREE-A DELIMITED BY ' '
' ' DELIMITED BY SIZE
THREE-B DELIMITED BY ' '
'.' DELIMITED BY SIZE
INTO THREE-C.
DISPLAY THREE-C.
EXIT-PROG.
STOP RUN.
输出如下所示：
-- METHOD ONE --
RALPH WIGGAM LIKES LEARNDING.
-- METHOD TWO --
RALPH WIGGAM LIKES LEARNDING.
-- METHOD THREE, NAIVE --
RALPH LIKES.
-- METHOD THREE, OK --
RALPH WIGGAM LIKES LEARNDING.
于 2012-04-06T21:47:47.390 回答