Groovy学习笔记-布尔求值

1.判断字符串为null或空字符串

def str = null
if(str)
    println 'str is not null'
else
    println 'str is null'

str = ''
if(str)
    println 'str is not null'
else
    println 'str is null'

/*output
str is null
str is null
*/

2.集合是否为空或Count ==0

list = null
if(list)
    println 'list is not null'
else
    println 'list is null'

list = []
if(list)
    println 'list is not null'
else
    println 'list is null'

/*output
    list is null
    list is null
*/

3.集合新增元素

def list = ['aaa'];
list<<'a'

println list