title: Error "command not found" when setting value to variable
body: <p>I have the following test.sh script:</p>
  
  <pre><code>#!/bin/bash
  foo=0
  bar=foo;
  ${bar}=1
  echo $foo;
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>./test.sh: line 4: foo=1: command not found
  0
  </code></pre>
  
  <p>Why the "command not found" error? How to change script to "echo $foo" outputs 1?</p>