Creating multiple files with content from shell

Question

One command to create 26 empty files:

touch {a..z}.txt

or 152:

touch {{a..z},{A..Z},{0..99}}.txt

A small loop to create 152 files with some contents:

for f in {a..z} {A..Z} {0..99}
do
    echo hello > "$f.txt"
done

You can do numbered files with leading zeros:

for i in {0..100}
do
    echo hello > "File$(printf "%03d" "$i").txt"
done

or, in Bash 4:

for i in {000..100}
do
    echo hello > "File${i}.txt"
done