Types of Dynamic Variables
Predefined Variables
As the name says these are predefined; ready to use. They are categorized based on their domain of usage and relevance.
1. Common:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomUUID |
It generates a random 36-character UUID. UUID is a Universal Unique Identifier that is used as a unique ID when saving data to databases and fetching them in O(1). Although it can be used for many applications it is most widely used as a Primary key for entities. |
8f010747-d22d-4f28-a4c0-2f44cabb5510, f2a3c8b3-6f08-40ed-854e-fce241781a5a |
|
$timestamp |
It returns the current UNIX timestamp in seconds since Epoch. Epoch is a popular and most widely used convention for computers to track time; here a fixed time called “Thursday 1st January 1970” is used as a reference to measure the time that has passed since then. For example, when you use this variable in the year 2024 it looks something like this 1704535541; this tells how many years, months, days, hours, minutes, seconds, and milli-seconds have passed after the Epoch. |
1704538732, 1704538740 |
2. Numbers, Texts and Colors:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomAlphaNumeric |
It returns a random alpha-numeric number. Any character from a-z and 0-9 can appear when you use this random variable. |
0, ‘0’, ‘e’,1,5 |
|
$randomHexColor |
It returns a random hex color code. The values are a special code that represents color values from 0 to 255, used in HTML, CSS, and SVG. Each hex code refers to a specific color, allowing designers and developers to communicate about the exact color they are referring to. |
#451e02, #6f3a2c |
|
$randomBoolean |
It returns either true or false. It is as simple as it sounds. If you want to explore how these work behind the scenes checkout Fakerjs npm package. They have detailed documentation available as to how to use additional options. |
true, false |
|
$randomInt |
It returns a random integer value between 0 and 1000. A fun use case would be to randomly assign a number to each participant in a lucky draw; beware of this returning a 0 to any customer. |
884, 183, 93 |
|
$randomAbbreviation |
It generates a random abbreviation. |
SCSI, JSON, COM, SMTP, GB, SSL, HTTP, RAM |
|
$randomColor |
It returns a random color in the text format. When you are playing Ludo, this could be useful to randomly assign colors so that Sheldon doesn’t take green color every time. (A Big Bang theory reference) |
sky blue, green, cyan, lime, tan |
3. Address, Location, Phone:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomPhoneNumber |
It returns a random 10-digit phone number. |
273-439-9587, 381-481-1518, 681-920-9004 |
|
$randomStreetAddress |
It returns a random street address |
8632 Thomas Port, 536 Schinner Flats, 510 Waters Harbor |
|
$randomCity |
It returns a city name at random. You can use this when you have to make a small talk with strangers for the question where are you from. |
St. Paul, Berwyn, Victormouth, New Carmelo. |
|
$randomLatitude |
It returns a random latitude coordinate. |
32.9050, 56.8508, -74.5084 |
4. Names:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomFirstName |
It returns a random first name. |
Gerson, Dominique, Bessie, Alejandra |
|
$randomLastName |
It returns a random last name. |
Quitzon, Auer, Maggio, Ferry |
|
$randomNamePrefix |
It returns a random name prefix. |
Dr., Mr., Miss, Ms, Mrs. |
5. Dates:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomDateFuture |
It returns random future datetime. |
Wed Jun 05 2024 16:07:00 GMT+0530 (India Standard Time), Sat Dec 28 2024 09:06:20 GMT+0530 (India Standard Time) |
|
$randomDateRecent |
It returns a recent datetime randomly. |
Sat Jan 06 2024 07:36:55 GMT+0530 (India Standard Time), Sat Jan 06 2024 17:10:17 GMT+0530 (India Standard Time) |
|
$randomMonth |
It returns a random month. |
April, February, June |
|
$randomWeekday |
It returns a random weekday |
Wednesday, Friday, Sunday |
6. Databases:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomDatabaseColumn |
It returns a random database column name |
comment, status, category, updatedAt |
|
$randomDatabaseType |
It returns any random data type that is usually stored in databases. |
smallestPostgreSQL(used in SQL and MYSQL), binary(all databases), geometry(SQL), serial(postgresql), point(PostgreSQLreturns) |
|
$randomDatabaseEngine |
It returns a random database engine. |
InnoDB, MyISAM, MEMORY, BLACKHOLE |
7. Domains, Username, and Emails:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomDomainName |
It returns a random domain name |
shawn.net, lafayette.biz, alaina.com, kamille.biz |
|
$randomEmail |
It returns a random email address. |
John.Batz@hotmail.com, Jamar_Ritchie@hotmail.com, Clint6@gmail.com |
|
$randomDomainWord |
It returns a random unqualified domain name. An unqualified domain name is a domain name that doesn’t have any dots. For example, “www” is an unqualified domain name. |
Examples: immanuel, lisandro, edwin |
|
$randomUserName |
It returns a random username. |
Noelia27, Carolina.Okuneva, Florencio30 |
8. Internet and IP Address:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomProtocol |
It returns a random internet protocol. It returns either http or https. |
HTTP, HTTPS |
|
$randomIP |
It returns a random IPv4 address. |
28.93.163.70, 68.45.188.68, 222.74.133.238 |
|
$randomIPV6 |
It returns a random IPv6 address. |
8c97:5a4a:3e83:c026:c06d:95c5:3003:99d9, cbd2:fadc:15a8:665f:457b:04d1:825a:6275 |
9. Files and Directories:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomFileName |
It returns a random file name; watch out for the uncommon extensions |
cross_platform_mesh_blockchains.ogx, coordinator.qxl, assistant_withdrawal.cxx |
|
$randomFileType |
It returns a random file type |
application, image, message, audio, message |
|
$randomDirectoryPath |
It returns a directory path |
/var/tmp, /usr/local/bin, /boot/defaults |
10. Images:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomImageDataUri |
It returns a random data image URI. |
data:image/svg+xml;charset=UTF-8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20version%3D%221.1%22%20baseProfile%3D%22full%22%20width%3D%22undefined%22%20height%3D%22undefined%22%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22grey%22%2F%3E%3Ctext%20x%3D%22NaN%22%20y%3D%22NaN%22%20font-size%3D%2220%22%20alignment-baseline%3D%22middle%22%20text-anchor%3D%22middle%22%20fill%3D%22white%22%3Eundefinedxundefined%3C%2Ftext%3E%3C%2Fsvg%3E |
11. Business:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomCompanyName |
It returns a random company name |
Mayer – Konopelski, Hahn, Haag and Hand, Kuhlman Group |
|
$randomBs |
It returns a random business speak; some buzzwords usedthe in the corporate world. |
morph front-end deliverables, harness B2B e-business, deliver extensible infomediaries |
|
$randomCompanySuffix |
It returns a random company suffix |
Group, LLC, Inc |
12. Finance:
| Variable Name | Description |
Examples |
|---|---|---|
|
$randomBankAccount |
It returns a random 8-digit bank account number. |
93838670, 18456375 |
|
$randomBankAccountName |
It returns a bank account name |
Investment Account, Auto Loan Account, Checking Account |
|
$randomCreditCardMask |
It returns a random masked credit card number |
2499, 6875, 1448 |
Note:
The examples are referred from official Postman documentation to be more accurate and Postman uses a library called Faker.js for random data generation.
Environment Variables
Defined within environments and scoped to requests within that environment.
- DEV_AWS_API_KEY: Store your API key of the URLDEV environment.
- LOCAL_BE_URL: Dynamically adjust the base URL for local, QA.
Collection Variables
Shared across all requests within a collection.
- PRODUCT_ID: Specify the product ID for testing with different products.
- AUTH_SERVICE_URL: Auth service URLand to be used in the collection.
Global Variables
Defined once and accessible from all environments and collections.
- COMPANY_NAME: Use your company name consistently across all tests.
Postman Dynamic Variables
Postman’s dynamic variables are powerful tools to help developers perform API testing with less effort. They provide flexible ways to inject and manage data directly into requests and scripts. They can be configured in the folder, environment, or even in a single request. They promote consistency and also by simplifying repetitive tasks they save a lot of time.
Table of Content
- Types of Dynamic Variables
- Step By Step Working with Dynamic Variables
- Examples of Postman Dynamic Variables
- Advanced Techniques and Tips
- Troubleshooting Dynamic Variables
- Conclusion