I want to return multiple values from a function written in groovy and receive them , but i am getting an error
class org.codehaus.groovy.ast.expr.ListExpression, with its value '[a, b]', is a bad expression as the left hand side of an assignment operator
My code is
int a=10
int b=0
println "a is ${a} , b is ${b}"
[a,b]=f1(a)
println "a is NOW ${a} , b is NOW ${b}"
def f1(int x) {
return [a*10,a*20]
}
You almost have it. Conceptually [ a, b ] creates a list, and ( a, b ) unwraps one, so you want (a,b)=f1(a) instead of [a,b]=f1(a).
int a=10
int b=0
println "a is ${a} , b is ${b}"
(a,b)=f1(a)
println "a is NOW ${a} , b is NOW ${b}"
def f1(int x) {
return [x*10,x*20]
}
Another example returning objects, which don't need to be the same type:
final Date foo
final String bar
(foo, bar) = baz()
println foo
println bar
def baz() {
return [ new Date(0), 'Test' ]
}
Additionally you can combine the declaration and assignment:
final def (Date foo, String bar) = baz()
println foo
println bar
def baz() {
return [ new Date(0), 'Test' ]
}
You can declare and assign the variables in which the return values are stored in one line like this, which is a slightly more compact syntax than that used in Justin's answer:
def (int a, int b) = f1(22)
In your particular case you may not be able to use this because one of the variables passed to f1 is also used to store a return value
int declarations inside the parentheses.
When running Groovy in the context of Jenkins pipeline job the above answers do not work (at least on version 2.60.2), but the following does:
node {
obj = ret2()
fw = obj[0]
lw = obj[1]
echo "fw=${fw}"
echo "lw=${lw}"
}
def ret2()
{
return [5, 7]
}
Or alternatively:
node {
obj = ret2()
fw = obj.a
lw = obj.b
echo "fw=${fw}"
echo "lw=${lw}"
}
def ret2()
{
return [a:5, b:7]
}