Comparing with NULL

[pm771]

Do I understand correctly that NULL is neither equal (==) nor not equal (!=) to any value? 

I know about isnull() function, but was under (apparently wrong) impression that NULL is  not equal to everything else.

Illustration:

| makeresults
| eval N=null
| eval i1=if(isnull(N), "N", "Y")
| eval i2=if(N != "Y", "N", "Y")

Result:

i1	i2
N	Y

Is it fully documented?

[pm771]

What I meant was:

| makeresults
| eval i1=if(null==null, "true", "false")
| eval i2=if(null!=null, "true", "false")

 The return will be false and false. 

[inventsekar]

soo, i thought to test this with integer and string..

| makeresults
| eval N="3"
| eval i1=if(N==3, "N", "Y")
| eval i2=if(N != "3", "N", "Y")

i1=N  and i2=Y 

| makeresults
| eval N=3
| eval i1=if(N==3, "N", "Y")
| eval i2=if(N != "3", "N", "Y") 

also produced the above result. 

(PS - i have given around 350+ karma points so far, received badge for that,.. maybe you also should start "Learn, Give Back, Have Fun")