[SOLVED] Assigning existing variable value to a new variable

Assigning existing variable value to a new variable

I want to assign a value of an existing variable to a new variable. The issues is that once the new variable gets assigned to a value of the existing variable it returns none instead of returning the existing variable value.

VAR1="Hello World"
VAR2="Let's concatenate"

VAR1+="$MyVar" # assigning to a new variable
echo "$VAR1"
echo "$MyVar" # This is the issue --> no value returned (intention is to return "Hello World")

The output is for this command (echo "$MyVar") is:

+ VAR1=
+ echo ''

Solution

You aren't defining a new variable named MyVar. You are appending the empty string resulting from the expansion of the non-existent variable to the value of VAR1.

You want

MyVar=$VAR1

to get the desired result.

An example of what += does do:

$ x=foo
$ echo "$x"
foo
$ x+=bar
$ echo "$x"
foobar