What is the difference between these task definition syntaxes in gradle?

Question

A)

task build << {  
  description = \"Build task.\"  
  ant.echo(\'build\')  
}

B)

task build {  
  description          


        

Answer 1

The first syntax defines a task, and provides some code to be executed when the task executes. The second syntax defines a task, and provides some code to be executed straight away to configure the task. For example:

task build << { println 'this executes when build task is executed' }
task build { println 'this executes when the build script is executed' }

In fact, the first syntax is equivalent to:

task build { doLast { println 'this executes when build task is executed' } }

So, in your example above, for syntax A the description does not show up in gradle -t because the code which sets the description is not executed until the task executed, which does not happen when you run gradle -t.

For syntax B the code that does the ant.echo() is run for every invocation of gradle, including gradle -t

To provide both an action to execute and a description for the task you can do either of:

task build(description: 'some description') << { some code }
task build { description = 'some description'; doLast { some code } }