Why for-in loop doesn't print what I want? [duplicate]

Question

I wrote in the terminal:

arr=(1 2 3)
for x in $arr; do
 echo $x
done

and it just prints '1'. Why doesn't it print 1 2 3 ?

Answer 1

Change

for x in $arr; do

to

for x in "${arr[@]}"; do

Answer 2

To expand to all the elements of an array, use "${arr[@]}"

for x in "${arr[@]}"; do

When you use the array name as an ordinary variable, without indexing it, it expands to the first element.