perfrom循环专门设计COBOL语言

COBOL语言

发布：1959年

作者：葛丽丝·穆雷·霍普

perfrom有四种类型：

❶perfrom until

❷perfrom varying

❸perfrom times

❹perfrom thru/through

注：Visual COBOL增加了perfrom遍历

perfrperfrom until(直到循环)

perform  until i>5

add 1 to i

end-perfrom

perfrom varying(迭代因子)

perfrom varying i from 1  by 1 until i>5

end-perfrom

注：设置步长，迭代因子不需要手动赋值累加i，而自动i加1(取决步长)

perfrom times(循环次数)

perfrom 5 times

end-perfrom

perfrom thru(执行段落)

perfrom a-routine thru z-routine

a-routine.

display 'Hello World'.

z-routone.

Visual COBOL

set content of v to ("AB","CD")

perform varying e as string through v

display e

end-perform