Scope is an enclosing context where values and expressions are associated. Use this tag for questions about different types of scope as well for questions where scope may be unclear.
Questions tagged [scope]
17524 questions
86
votes
3 answers
Derived template-class access to base-class member-data
This question is a furtherance of the one asked in this thread.
Using the following class definitions:
template
class Foo {
public:
Foo (const foo_arg_t foo_arg) : _foo_arg(foo_arg)
{
/* do something for foo */
}
T…
Shamster
- 2,092
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85
votes
6 answers
Why can't we define a variable inside an if statement?
Maybe this question has been answered before, but the word if occurs so often it's hard to find it.
The example doesn't make sense (the expression is always true), but it illustrates my question.
Why is this code valid:
StringBuilder sb;
if ((sb =…
comecme
- 6,086
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- 67
85
votes
11 answers
What do curly braces in Java mean by themselves?
I have some Java code that uses curly braces in two ways
// Curly braces attached to an 'if' statement:
if(node.getId() != null)
{
node.getId().apply(this);
}
// Curly braces by themselves:
{
List copy = new…
Paul Wicks
- 62,960
- 55
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83
votes
3 answers
Use external variable in array_filter
I've got an array, which I want to filter by an external variable.
The situation is as follows:
$id = '1';
var_dump($id);
$foo = array_filter($bar, function($obj){
if (isset($obj->foo)) {
var_dump($id);
if ($obj->foo == $id)…
Sander Koedood
- 6,007
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- 34
82
votes
4 answers
Variable scopes in Python classes
Declaring a variable in a class (outside of a function): all class functions can access it (basically a public variable)
Declaring a variable inside a function inside a class: only that function can access it (it's in that function's…
jason
- 4,721
- 8
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- 45
82
votes
2 answers
Scope of variable within "with" statement?
I am reading only firstline from python using :
with open(file_path, 'r') as f:
my_count = f.readline()
print(my_count)
I am bit confused over scope of variable my_count. Although prints work fine, would it be better to do something like…
danish sodhi
- 1,793
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- 31
81
votes
3 answers
Static (Lexical) Scoping vs Dynamic Scoping (Pseudocode)
Program A()
{
x, y, z: integer;
procedure B()
{
y: integer;
y=0;
x=z+1;
z=y+2;
}
procedure C()
{
z: integer;
procedure D()
{
x: integer;
x = z…
petrov
- 1,085
- 3
- 12
- 13
80
votes
5 answers
Scope issues with Angular UI modal
I'm having trouble understanding/using the scopes for an angular UI modal.
While not immediately apparent here, I have the modules and everything set up correctly (as far as I can tell), but these code samples in particular are where I'm finding…
coblr
- 3,008
- 3
- 23
- 31
79
votes
4 answers
Python overwriting variables in nested functions
Suppose I have the following python code:
def outer():
string = ""
def inner():
string = "String was changed by a nested function!"
inner()
return string
I want a call to outer() to return "String was changed by a nested…
Ord
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- 42
79
votes
4 answers
Private inner classes in C# - why aren't they used more often?
I am relatively new to C# and each time I begin to work on a C# project (I only worked on nearly mature projects in C#) I wonder why there are no inner classes?
Maybe I don't understand their goal. To me, inner classes -- at least private inner…
Sylvain Rodrigue
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- 67
79
votes
1 answer
Nested templates with dependent scope
What is dependent scope and what is the meaning of typename in the context of the following error?
$ make
g++ -std=gnu++0x main.cpp
main.cpp:18:10: error: need 'typename' before 'ptrModel >::Type' because…
user383352
- 5,033
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- 20
79
votes
6 answers
Mixing extern and const
Can I mix extern and const, as extern const? If yes, does the const qualifier impose it's reign only within the scope it's declared in or should it exactly match the declaration of the translational unit it's declared in? I.e. can I declare say…
legends2k
- 31,634
- 25
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78
votes
6 answers
In Python 2, how do I write to variable in the parent scope?
I have some code like:
def example():
# other logic omitted
stored_blocks = {}
def replace_blocks(m):
block = m.group(0)
block_hash = sha1(block)
stored_blocks[block_hash] = block
return '{{{%s}}}' %…
ThiefMaster
- 310,957
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76
votes
2 answers
What do the curly braces do in switch statement after case in es6?
What's the difference between:
switch (expression) {
case:
somethings;
break;
}
and
switch (expression) {
case: {
somethings;
break;
}
}
At first I thought that I could return an object literal like so, but it…
Aurimas
- 2,577
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75
votes
1 answer
What is the difference between Dim, Global, Public, and Private as Modular Field Access Modifiers?
In VB6/VBA, you can declare module-level variables outside of a specific Sub or Function method. I've used Private and Public before inside modules and understand them like so:
Public - visible to all code inside the module and all code outside…
Ben McCormack
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