bash shell nested for loop

The question does not contain a nested loop, just a single loop. But THIS nested version works, too:

# for i in c d; do for j in a b; do echo $i $j; done; donec ac bd ad b

One one line (semi-colons necessary):

for i in 0 1 2 3 4 5 6 7 8 9; do for j in 0 1 2 3 4 5 6 7 8 9; do echo "$i$j"; done; done

Formatted for legibility (no semi-colons needed):

for i in 0 1 2 3 4 5 6 7 8 9do    for j in 0 1 2 3 4 5 6 7 8 9    do         echo "$i$j"    donedone

There are different views on how the shell code should be laid out over multiple lines; that's about what I normally use, unless I put the next operation on the same line as the do (saving two lines here).

#!/bin/bash# loop*figures.bashfor i in 1 2 3 4 5  # First loop.do    for j in $(seq 1 $i)    do        echo  -n "*"     done    echo doneecho# outputs# *# **# ***# ****# *****for i in 5 4 3 2 1 # First loop.do    for j in $(seq -$i -1)    do        echo  -n "*"     done    echo done# outputs# *****# ****# ***# **# *for i in 1 2 3 4 5  # First loop.do    for k in $(seq -5 -$i)    do        echo -n ' '    done    for j in $(seq 1 $i)    do        echo  -n "* "     done    echo doneecho# outputs#     * #    * * #   * * * #  * * * * # * * * * * for i in 1 2 3 4 5  # First loop.do    for j in $(seq -5 -$i)    do        echo  -n "* "     done    echo     for k in $(seq 1 $i)    do        echo -n ' '    donedoneecho# outputs# * * * * * #  * * * * #   * * * #    * * #     *exit 0