Beware of command substitution in bash

It's dangerous to use a loop with ls results in your bash scripts:

for i in $(ls)

Unix/Linux allows for almost any character in file names, including new lines and spaces. Then, what happens when there's a file with a space in its name:

╭─mansuro@localhost  ~/workspace/new_dir 

╰─$ touch some\ file

╭─mansuro@localhost  ~/workspace/new_dir  

╰─$ ls

some file

╭─mansuro@localhost  ~/workspace/new_dir  

╰─$ (for i in $(ls); do echo $i; done)

some

file

 As you can see, the file was treated as two different arguments, and that would have undesirable effects in your bash scripts.
How can we fix this? We could change 

for i in $(ls)

to

for i in *

╭─mansuro@localhost  ~/workspace/learning/Terminal/new_dir  

╰─$ (for i in *; do echo $i; done) 

some file

And you're done, your bash script works the way you want it to.