# Assertion error, why?

**URL:** <https://verificationacademy.com/forums/t/assertion-error-why/29284>\
**Category:** SystemVerilog\
**Tags:** SystemVerilog\
**Created:** [March 27, 2014, 8:23am UTC](https://verificationacademy.com/forums/t/assertion-error-why/29284 "2014-03-27T08:23:22Z")\
**Posts on this page:** 1\
**Showing post:** 5

<div class="post-metadata">

**Author:** ![Liangjun\_Wang](https://verificationacademy.com/forums/letter_avatar_proxy/v4/letter/l/65b543/32.png) [@Liangjun\_Wang](https://verificationacademy.com/forums/u/Liangjun_Wang)\
**Post date:** [March 28, 2014, 1:23am UTC](https://verificationacademy.com/forums/t/assertion-error-why/29284/5 "2014-03-28T01:23:16Z")

</div>

_In reply to [dave\_59](https://verificationacademy.com/forums/t/assertion-error-why/29284/4):_

Thanks Dave, it works!

```
It is explicitly demonstrated in LRM that "randomize(null)" will check all constraints in the class, but I don't find an explicit demonstrtion that "randomize(xx)" will also check all constraints, maybe I have missed somthing in LRM. It is easily misunderstood that "randomize(xx)" will only check constraints specified with "xx".

```

---

_[View the full topic](https://verificationacademy.com/forums/t/assertion-error-why/29284)._