编辑把一个字符串首尾颠倒排序

clear
x=""

@1,2 say"请输入字符：" get s default space(20)
read

for i=1 to len(s)
x=substr(s,i,1)+x
endf
?x

clear
x=""

@1,2 say"请输入字符：" get s default space(20)
read

for i=1 to len(s)
x=substr(s,i,1)+x
endf
?x

clear
x=""

@1,2 say"请输入字符：" get s default space(20)
read

for i=1 to len(s)
x=substr(s,i,1)+x
endf
?x

clear
accept "请输入一个字符串： " to a default space(20)
for b=len(a) to 1 step -1
??space(20)+substr(a,b,1)
endfor