Groovy使用多赋值

def splitName(fullName){    fullName.split(' ')}def (firstName,lastName) = splitName('James Bone')println "$lastName,$firstName $lastName"

运行结果：
Bone,James Bone

上述代码可以把spiltName()结果赋给一对变量firstName,lastName

还可以使用该特性来交换变量，无需创建中间变量

def name1 = "Thomson"def name2 = "Thompson"println "$name1 and $name2"(name1,name2) = [name2,name1]println "$name1 and $name2"

运行结果：
Thomson and Thompson
Thompson and Thomson

当变量与值得数目不匹配。Groovy也会做处理

def (String cat,String mouse) = ['Tom','Jerry','Spike','Tyke']println "$cat and $mouse"

运行结果：Tom and Jerry

Groovy会舍弃多余的值

def (first,second,third) = ['Tom','Jerry']println "$first,$second,$third"

运行结果：Tom,Jerry,null

Groovy会将多余的值设置为null

如果多余的变量不能设置为null的基本类型，Groovy会抛出异常。

def (String cat,String mouse,int a) = ['Tom','Jerry']println "$cat and $mouse"

结果：Caught: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' insteadorg.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead

在Groovy2.x中，只要可能，int就会被看做基本类型，而非Integer