title: Gradle: Why plus operator causes dupe strings to concat?
body: <p>In my <code>build.gradle</code> file in Android Studio, I'm creating a new APK file name with the following:</p>
  
  <pre><code>def newApkName = rootProject.name + "-" + variant.versionName + variant.buildType.versionNameSuffix
  </code></pre>
  
  <p>This is causing the following to print out: <em>app-2.2.0-debug-debug</em></p>
  
  <p>However if I do the following instead:</p>
  
  <pre><code>def newApkName = rootProject.name + "-" + variant.versionName
  newApkName.concat(variant.buildType.versionNameSuffix)
  </code></pre>
  
  <p>It correctly prints out: <em>app-2.2.0-debug</em></p>
  
  <p>I'm new to gradle, so I'm very confused why using the plus operator to concat is causing a dupe string to appear...where as using the concat method doesn't.  Any insight on why this is?</p>