Question

在不使用临时变量的情况下,在COBOL中添加字面的分辨率是否有什么变化?

在以下法典中要说:

MOVE "HELLO" TO MY-VAR.
MOVE MY-VAR(1:3) TO SUB-STR.

Is there any way to do the same thing, but without MY-VAR?

EDIT: I did tried following code, but it s failed.

MOVE "HELLO"(1:3) TO SUB-STR   * COMPILE ERROR

Answer 1

You can accomplish what you are trying to do by type-laundering the literal through a function. You can then substring, or reference modify, the output of the function. Consider that calling reverse twice on the same data returns the original data.

Move function reverse                           
 ( function reverse( 
       abcdefg  
   )
 ) (3:1) to text-out

以上将产生一个排在案文的正文。

Answer 2

Of course, the example code in your question does not make any sense, as why would you write "HELLO"(1:3) when you could just write "HEL".

因此,你必须想在参考变数领域使用变量(或2)。

如果你想要获得字面上的第一个N级特性,你可以通过在destination 项目上使用参考词典来这样做。例如,如果您汇编并管理以下方案:

   IDENTIFICATION DIVISION.
   PROGRAM-ID. HELLO.
   DATA DIVISION.
   WORKING-STORAGE SECTION.
   01 LEN          PIC 99 VALUE 8.
   01 SUB-STR      PIC X(80).
   PROCEDURE DIVISION.
       MOVE "HELLO WORLD" TO SUB-STR(1:LEN).
       DISPLAY SUB-STR.
       STOP RUN.

取得结果:

HELLO WO

不幸的是,这种方法只有在你想要字面描述的第一个N特性时才会奏效。

此外,在你开始之前,扼杀目的地必须是空洞的。在上述方案中,如果您修改了<代码>SUB-Chap>/code>的定义:

01 SUB-STR      PIC X(80) VALUE "BLAH BLAH BLAH".

其后,方案的实施结果如下:

HELLO WOH BLAH

Answer 3

把“推进剂”变成一个不变的领域。

IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 LITERAL-HELLO PIC X(5) VALUE  HELLO .
PROCEDURE DIVISION.
    DISPLAY LITERAL-HELLO(1:3).
    STOP RUN.

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