How to concatenate string variables in Bash

Question

In PHP, strings are concatenated together as follows:

$foo = \"Hello\";
$foo .= \" World\";

Here, $foo becomes \"Hello World\"

Answer 1

I wanted to build a string from a list. Couldn't find an answer for that so I post it here. Here is what I did:

list=(1 2 3 4 5)
string=''

for elm in "${list[@]}"; do
    string="${string} ${elm}"
done

echo ${string}

and then I get the following output:

1 2 3 4 5