shell-嵌套循环之九九乘法表

for循环嵌套

!/bin/bash

for i in seq 1 9;
do
for j in seq 1 $i;
do
let "k=$i$j"
echo -ne "$i$j=$k\t"
done
echo
done
输出结果

while循环嵌套

!/bin/bash

a=1
while [ $a -le 9 ]
do
b=1
while [ $b -le $a ]
do
let "c=$a$b"
echo -ne "$a$b=$c\t"
let "b+=1"
done
echo
let "a+=1"
done
输出结果

until循环嵌套

!/bin/bash

a=1
until [ $a -gt 9 ]
do
b=1
until [ $b -gt $a ]
do
let "c=$a$b"
echo -ne "$a$b=$c\t"
let "b+=1"
done
echo
let "a+=1"
done
输出结果：