title: Descending sort by value of a Hash in Ruby
body: <p>My input hash: <code>h = { "a" =&gt; 20, "b" =&gt; 30, "c" =&gt; 10 }</code></p>
  
  <p>Ascending sort: <code>h.sort {|a,b| a[1]&lt;=&gt;b[1]}   #=&gt; [["c", 10], ["a", 20], ["b", 30]]</code></p>
  
  <p>But, I need <code>[["b", 30], ["a", 20], ["c", 10]]</code></p>
  
  <p>How is can we make it work the other way around, what does <code>&lt;=&gt;</code> mean?</p>