《COBOL论文翻译》-毕业论文.doc

PAGE PAGE 49 使用COPY，CALL和其他语句来提高编程效率 Ⅰ.Nancy Stern Ⅱ.Robert A. Stern Ⅲ.James P. Ley Ⅰ. 霍夫斯特拉大学 Ⅱ. 拿骚社区学院 Ⅲ. 威斯康星大学斯托特 关键词： COPY, CALL, STRING, UNSTRING, OVERFLOW, POINTER, FD, OF, IN, PIC, IDENTIFICATION DIVISION, PROGRAM-ID, DATA DIVISION, REPLACING, BY, USING, PROCEDURE DIVISION, LINKAGE SECTION, WORKING-STORAGE SECTION, EXIT PROGRAM, COBOL, STOP RUN, CALLING， DISPLAY，CONTENT， DELIMITED， VALUE， ACCEPT， ON， WITH， MOVE， SUBTRACT, INTO, ALL, END-UNSTRING. 参考文献： 10th EDITION 《COBOL FOR THE 21ST CENTURY》 Ⅰ.Nancy Stern Hofstra Ⅱ.Robert A. Stern Nassau Ⅲ.James P. Ley University of Wisconsin-Stout Copyright ? 2003 by John Wiley Sons, Inc. Improving Program Productivity Using The COPY, CALL, and Other Statements OBJECTIVES To familiarize you with The COPY statement for copying parts of a program that are stored in a library. The CALL statement for executing called programs as subroutines. Text manipulation with the STRING and UNSTRING statements. CONTENTS COPY STATEMENT Introduction Entries that Can Be Copied An Example The Full Format for the COPY Statement CALL STATEMENT Why Use a CALL Statement? Format of the CALL Statement Called Program Requirements Calling Program Requirements Examples TEXT MANIPULATION WITH STRING AND UNSTRING STATEMENTS The STRING Statement The Basic Format OVERFLOW Option POINTER Option General Rules for Using the STRING The UNSTRING Statement The Basic Format General Rules for Using the UNSTRING END-OF-CHAPTER AIDS Chapter Summary Key Terms COPY STATEMENT INTRODUCTION A COPY statement is used to bring into a program a series of prewritten COBOL entries that have been stored in a library. Copying entries from a library, rather than coding them, has the following benefits: (1) it could save a programmer a considerable amount of coding and debugging time; (2) it promotes program standardization since all programs that copy entries from a library will be u