EL "" will it be interpreted as zero ?

[Kathiresan Chinna]

Hi there,

See the following EL and return values

1. ${ "" > -1 } --> true
2. ${ "" > 0 } --> false
3. ${ "" == 0 } --> false
4. ${ "" < 1 } --> true

As per the JSp spec Coerce A to Number type N
• If A is null or "", return 0.

But the 3 is evaluated false.
Is this correct ?

Thanks in Advance
Kathiresan

[Milton Ochoa]

very intesting your question,

but i wonder, why you got there, i mean, compare the "" sttring with number.

Maybe the comparation is about strings and not numbers.

[Kathiresan Chinna]

I have to test this for exam purpose.

[Milton Ochoa]

I am preparing for the exam too.

are you taking a simulator? mock exam?

[Kathiresan Chinna]

Hi, I am reading HFSJ book and practise from that question.

[Milton Ochoa]

on enthuware says on one answer.

...Since none is "", it will be interpreted as 0...

and none is declarated like String none = "";

but they mention (JSP 2.3.5.1) too. But there say nothing about that.

[Abdul Rahman]

As per HFSJ 1st edition and as per JSP2.0 spec, for arithmetic operation, EL treats the null values as Zero.
For logical operation, EL treats null values as false.

[Abdul Rahman]

As per HFSJ 1st edition and as per JSP2.0 spec, for arithmetic operation, EL treats the null values as Zero.
For logical operation, EL treats null values as false.

3. ${ "" == 0 } --> false

This will return true.

[Kathiresan Chinna]

Hello,

I am using Tomcat 6.0.18
I got ${ "" == 0 } --> false

Kathir

[Abdul Rahman]

Hi Kathy,
As per JSP2.0 spec and as per Tomcat5.0 (the one i'm using), i got that result to be true.
We'll have to look the jsp version supported by tomcat6. and the spec of that jsp version.