Cannot access parameter in scripted pipeline - jenkins

Question

I am trying to pass parameters to a scripted pipeline. From reading the docs, it should be simple, but I keep getting an error. What am I doing wrong?
Here is the code:
node("spvlanautomation01.lab.dtcc.com") {
parameters {
string(name: 'VLAN', defaultValue: '', description: '')
}
stage("Find VLAN File") {
echo "VLAN is ${params.VLAN}"
}
}
I've tried
echo "VLAN is ${VLAN}"
...and it didn't work either
Here is the error I get
Started by user anonymous
[Pipeline] node
Running on spvlanautomation01.lab.dtcc.com in /home/jenkins/workspace/build-vlan
[Pipeline] {
[Pipeline] stage
[Pipeline] { (Find VLAN File)
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
groovy.lang.MissingPropertyException: No such property: params for class: WorkflowScript
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:53)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.getProperty(ScriptBytecodeAdapter.java:458)
at com.cloudbees.groovy.cps.sandbox.DefaultInvoker.getProperty(DefaultInvoker.java:26)
at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:20)
at WorkflowScript.run(WorkflowScript:6)
at ___cps.transform___(Native Method)
at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.get(PropertyishBlock.java:74)
at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)
at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.fixName(PropertyishBlock.java:66)
at sun.reflect.GeneratedMethodAccessor675.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
at com.cloudbees.groovy.cps.Next.step(Next.java:58)
at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:154)
at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:164)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:324)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$100(CpsThreadGroup.java:78)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:236)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:224)
at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:47)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:112)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Finished: FAILURE

Answer 1

You have defined the parameters with Declarative Pipeline syntax. For Scripted Pipelines, the syntax is:
properties([
parameters([
string(name: 'VLAN', defaultValue: '', description: '')
])
])
node("spvlanautomation01.lab.dtcc.com") {
stage("Find VLAN File") {
echo "VLAN is ${params.VLAN}"
}
}
Note: The syntax properties([ parameters([...]) ]) also works in Declarative Pipelines.