Built-in JMeter Functions

JMeter allows you to conduct performance tests on your application by using any type of request. During these tests, we sometimes need to create new data, timestamp or maybe manipulate a response.

For these purposes, JMeter provides built-in functions easily adaptable to your tests. Let’s explore the ones that you might need during a test.

Random String

In order to create a random string in JMeter there are a few different ways.

Examples:

${__RandomString(5)} This will create a random string, It can be readable or not.

${__RandomString(5,ABCD123)} This will create a random string containing only the alphanumeric values that you provide.

${__RandomString(5,,var)} This will create a random string, then assign the value to a variable. So you will be able to use that variable in another script by using ${var} expression. Second parameter for RandomString function is optional.

Random Number

In order to create a random string in JMeter there are a few different ways.

Examples:

${__Random(5)} This will create a random number with defined length.

${__Random(5,var)} This will create a random number with defined length, then assign the value to a variable. So you will be able to use that variable in another script by using ${var} expression.

UUID

A universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems. In order to create one in JMeter, you should us __UUID() functionality. UUID is almost unique as its length and random

${UUID()} and you will have a value like that 0c7dba7e-7587-46d0-88f2-dfe577b88432

Split String

In case you need to split a String with a delimiter, you can use ${SPLIT()} functionality.

Just create a BeanShell Processor where you would want the split operation to happen. Then add this ${__split(${param},splitParam,|)} in the beanshell script field.

1st Parameter: Parameter that you would want to split.

2nd Parameter: After the split, splitted values will be assigned to this variable. You need to define index when using it.

3rd Parameter: Delimiter that you have in the String.

Example:

Param = canberk|akduygu|loadium

splitParam_1 = canberk

splitParam_2 = akduygu

splitParam_3 = loadium

Time

You can use Time functionality to get current time with different formats. You can specify a date time format to format time value.

${__time(dd/MM/yyyy,)} will get you 02/12/2018

${__time(dd-mmm-yyyy hh:mm,)} will get you 02-12-2018 12:22

${__time()} will get you the timestamp like 1598723200239

There are many other functions that you would use with JMeter but in case those functions are not sufficient for you, JavaScript is here to help you.

JavaScript

You can use __javaScript() function and pass any javascript code as a parameter and do extreme stuff also.

Examples:

Create a number between 0-10

${__javaScript(Math.floor(Math.random() * 10))}

Compare a variable to a hardcoded string then storing true/false result to a variable.

${__javaScript(“${username}”==”canberk”,found)}