Questions on short and pointer member variable

[D. Susman]

Hi,

1) When I define a variable like "short var", is it by default signed
or unsigned?
2) Say I have a class storing a pointer member variable. Is the
pointer assigned to 0 upon initialization of a class object
automatically or am I supposed to do it myself in the via
initialization list?

Thanks.

 

[Ian Collins]

Hi,

1) When I define a variable like "short var", is it by default signed
or unsigned?
Signed.

2) Say I have a class storing a pointer member variable. Is the
pointer assigned to 0 upon initialization of a class object
automatically or am I supposed to do it myself in the via
initialization list?

You have to initialise it.

 

[Kai-Uwe Bux]

Hi,

1) When I define a variable like "short var", is it by default signed
or unsigned?

"short var" will declare a variable of type short int, which is signed. See
[7.1.5.2] and Table 7 for details.

2) Say I have a class storing a pointer member variable. Is the
pointer assigned to 0 upon initialization of a class object
automatically or am I supposed to do it myself in the via
initialization list?

Members that are not of class type (e.g., pointers, arithmetic types, enums)
have indeterminate initial value unless you initialize them explicitly. See
[8/9] for details.


Best

Kai-Uwe Bux

 

[Micah Cowan]

Hi,

1) When I define a variable like "short var", is it by default signed
or unsigned?

For all of the standard integer types except for char, not specifying
signed or unsigned gives exactly the same semantics as if you had
specified "signed".

(char is a distinct type from either signed char or unsigned char, but
is required to have the same representation and set of values as one
of those.)

2) Say I have a class storing a pointer member variable. Is the
pointer assigned to 0 upon initialization of a class object
automatically or am I supposed to do it myself in the via
initialization list?

You need to do it explicitly; it won't be automatically initialized.

 

[Ron Natalie]

Hi,

1) When I define a variable like "short var", is it by default signed
or unsigned?

The absence of the word signed or unsigned implies signed for all types
except char. There are three distinct char types, char, unsigned char,
signed char. The char type is implementation defined as either signed
or unsigned but is a distinct type.