JMeter "if controller" with parameters?

Question

I was reading the JMeter documentation and came across this info box about "If Controllers":

No variables are made available to the script when the condition is interpreted as Javascript. If you need access to such variables, then select "Interpret Condition as Variable Expression?" and use a __javaScript() function call. You can then use the objects "vars", "log", "ctx" etc. in the script.

I don't quite follow this. Does this mean if I want access to a "User Defined Parameter" then I can access it only by writing some JavaScript? The example that follows this box then refers to "${COUNT}"

Could someone clarify the usage of the If Controller, maybe with an example or two?

Answer 1

All these answers are wrong! You need to put the variable reference in quotes, like so:

"${my_variable}"=="foo"

Answer 2

You can simply use something like

${my_variable}=='1'

Sometimes JMeter documentation can be confusing :)

Edit 27 september 2017:

The answer here works but has a very bad performance impact when number of threads exceeds 40.

See below for correct and most performing answer:

• https://stackoverflow.com/a/46976447/460802

See:

• https://bz.apache.org/bugzilla/show_bug.cgi?id=61675

Answer 3

The If Controller will internally use JavaScript to evaluate the condition but this can have a performance penalty.

A better option (default starting from JMeter 4, see Bug 61675 ) is to check the box Interpret Condition as Variable Expression?, then in the condition field you have 2 options:

• Option 1: Variable. Use a variable that contains true or false. For example if you want to test if last sample was successful, you can use

  ${JMeterThread.last_sample_ok}
  

  Screenshot:

  or any variable you want that contains true or false

  ${myVar}
  

• Option 2: Function. Use a function (${__jexl3()} is advised) to evaluate an expression that must return true or false. For example if COUNT is equal to 1:

  ${__jexl3("${COUNT}"== "1",)}
  

  OR

  ${__jexl3(${COUNT}== 1,)}
  

  Screenshot:

Starting with 4.0, if you don't use the checkbox Interpret Condition as Variable Expression?, then this RED warning will be displayed:

If you'd like to learn more about JMeter and performance testing this book can help you: Master Apache JMeter -- From load testing to DevOps.

Answer 4

UNCHECK the CHECKBOX "Interpret condition as variable expression"

I wasted a couple of hours without unchecking this checkbox. It worked with and without semicolon(;) at the end of the statement. Make sure that you have set the User-Defined Variables before calling the if controller.

All the following variations worked for me in Jakarta Jmeter 1.5

• ${__javaScript("${HOMEPAGE}"=="Y")}
• ${__javaScript("${HOMEPAGE}"=="Y")};
• "${HOMEPAGE}"=="Y"
• "${HOMEPAGE}"=="Y";

Answer 5

God bless the http://habrahabr.ru Have tried until found these.

Using the quotes was my solution.

Answer 6

As Gerrie said you need to check your variable

${my_var} == 'value'

But be careful with the 'User Defined Variables'

Note that all the UDV elements in a test plan - no matter where they are - are processed at the start.

That basically means that you cannot define 'User Defined Variables' inside an 'If Controller'. Take a look to the 'BeanShell' instead.

Answer 7

Replace: ${my_variable}=='1' with "${my_variable}" == "1"

Answer 8

if it's string value pass as below and its performance effective

${__groovy("${key}"=="value")}

Answer 9

I have used ${code_g1}== 200 in condition and it worked for me.