What does the exclamation mark in C language mean?

Question

I was reading a code and I found these "!" all over the place what is it supposed to do ? this is a part from the code I found it in :

 if (!piocherMot(motSecret))
    exit(0);

piocherMot is a function in another file while "motsecret" is a variable in my main code.

For the future, try asking Google your question first. Searching "What does the exclamation mark in C language mean" in Google has many relevant results. — Kevin, Mar 18 '19 at 17:22

score 2 · Answer 1 · answered Mar 18 '19 at 16:23

2

This

is logical NOT operator & its a unary operator i.e it takes only one operand, result of this operator is either true(1) or false(0). Truth table of logical NOT operator is

 A    !A
----------
| 0  |  1 |
| 1  |  0 |
----------

Hence if piocherMot(motSecret) results in true i.e !1 which is 0 then if block will not get executes, in reverse case it gets executes.

if(!1) { /* 0 i.e if block won't executes */
}

And

if(!0) { /* 1 i.e if blocks executes */
}

answered Mar 18 '19 at 16:23

Achal

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why downvoting ? It's the answer, even thougth that the question is really basic. – Tom's Mar 18 '19 at 16:28
I'm not sure what else you guys would want from an answer to this question. This covers it IMHO. – CoffeeTableEspresso Mar 18 '19 at 16:49

What does the exclamation mark in C language mean?

1 Answers1