Gradle def vs ext

Question

What is the difference between using ext.varname and def varname. E.g. the following code seems to work the same:

task copyLicenses {     def outDir = project.buildDir.absolutePath + '/reports/license/'      doLast {         copy {             from 'licenses'             into outDir             include '*'         } 

seems to work exactly the same as

task copyLicenses {     ext.outDir = project.buildDir.absolutePath + '/reports/license/'      doLast {         copy {             from 'licenses'             into outDir             include '*'         } 

Answer 1

Keyword def comes from Groovy and means that variable has local scope.

Using ext.outDir means that you add property outDir to ExtraPropertiesExtension, think of it like project has a map of properties with name ext, and you put your property in this map for later access.