title: How to change from -source 1.6 to -source 7 in IntelliJ IDEA
body: <p>I' trying to build a in IntelliJ IDEA project that is not mine and I got the following error:</p>
  
  <p><em>java: diamond operator is not supported in -source 1.6
    (use -source 7 or higher to enable diamond operator)</em></p>
  
  <p>How do I change this setting in IntelliJ IDEA?</p>