Groovy是否有合并2张地图的方法？

Question

First map is default options [a: true, b: false] . Second map - options passed by user [a:false] . Does Groovy has maps merge method to obtain [a: false, b:false] ?

It's not problem to implement it in Groovy. I'm asking about method out of the box

Answer 1

You can use plus:

assert [ a: true, b: false ] + [ a: false ] == [ a: false, b: false ]

Or left shift:

assert [ a: true, b: false ] << [ a: false ] == [ a: false, b: false ] 

The difference is that << adds the right hand map into the left hand map . When you use + , it constructs a new Map based on the LHS , and adds the right hand map into it