NSAssert doesn't work

Question

I'm trying to use NSAssert in my code but it doesn't do a thing.

In this piece of code, the assertion should fail but doesn't:

    MSLog(@"cross.obj = %@",[cross obj]);
    NSAssert([cross obj]!=nil,@"[cross obj] == nil");

The output of this is:

cross.obj = (null)

What could be the problem?

For some reason `NS_BLOCK_ASSERTIONS` is set. – Kristina May 31 '11 at 17:05 — Kristina, May 31 '11 at 17:05

score 3 · Accepted Answer · answered May 31 '11 at 17:08

3

NS_BLOCK_ASSERTIONS blocks assertions from functioning. Try deleting the definition.

answered May 31 '11 at 17:08

Alexsander Akers

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score 1 · Answer 2 · edited Oct 17 '12 at 14:10

1

The reason behind this is that there is a difference between a nil and a null value.

So please check it with other examples.

It will work.

edited Oct 17 '12 at 14:10

keyser

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answered Oct 17 '12 at 14:06

Naveen

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nil and NULL are same values. Instead, [NSNull null] is object with non-nil value. – Borzh Sep 10 '16 at 18:04

Nikolai Ruhe · Answer 3 · 2011-05-31T17:07:04.447

0

The reason might be that the result from [cross obj] is [NSNull null], not nil.

The output probably is <null> which does not mean NULL or nil but the NSNull singleton object. This object is used as a placeholder where nil is not an option (for instance in NSArrays).

Another reason might be that the NS_BLOCK_ASSERTIONS preprocessor macro is defined which disables NSAssert.

edited May 31 '11 at 17:07

answered May 31 '11 at 17:00

Nikolai Ruhe

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`[cross obj]!=nil` evaluates to `FALSE` – Kristina May 31 '11 at 17:06

NSAssert doesn't work

3 Answers3