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if (key in object) or if(object.hasOwnProperty(key)
...type
If we want to check that some property exist on the prototype, logically, we would say:
console.log(('name' in o) && !o.hasOwnProperty('name')); //false
console.log(('gender' in o) && !o.hasOwnProperty('gender')); //true - it's in prototype
Finally:
So, regarding to statem...
MySQL stored procedure vs function, which would I use when?
...s:
A procedure does not return a value. Instead, it is invoked with a CALL statement to perform an operation such as modifying a table or processing retrieved records.
A function is invoked within an expression and returns a single value directly to the caller to be used in the expression.
You c...
How to check a not-defined variable in JavaScript
...ue for things that don't exist, undefined. The DOM returns null for almost all cases where it fails to find some structure in the document, but in JavaScript itself undefined is the value used.
Second, no, there is not a direct equivalent. If you really want to check for specifically for null, do:
...
grep a file, but show several surrounding lines?
...
Ok, but what if want to show all lines of output after the match? grep -A0 and grep -A-1 don't cut it...
– g33kz0r
Jul 22 '11 at 2:18
...
How does autowiring work in Spring?
...
First, and most important - all Spring beans are managed - they "live" inside a container, called "application context".
Second, each application has an entry point to that context. Web applications have a Servlet, JSF uses a el-resolver, etc. Also, th...
Can we have functions inside functions in C++?
...rm of a lambda:
int main() {
// This declares a lambda, which can be called just like a function
auto print_message = [](std::string message)
{
std::cout << message << "\n";
};
// Prints "Hello!" 10 times
for(int i = 0; i < 10; i++) {
print...
How do I use Assert.Throws to assert the type of the exception?
... is correct:
var ex = Assert.Throws<ArgumentNullException>(() => foo.Bar(null));
Assert.That(ex.ParamName, Is.EqualTo("bar"));
You can also use the fluent API for doing these asserts:
Assert.That(() => foo.Bar(null),
Throws.Exception
.TypeOf<ArgumentNullException>()
.With....
How can I pad a String in Java?
...glen3b: For an individual utility, like these string padding helpers, it really makes no difference which lib to use. That said, Guava is overall a more modern, cleaner and better documented lib than its counterparts in various Apache Commons projects (Commons Lang, Commons Collections, Commons IO, ...
Removing item from vector, while in C++11 range 'for' loop?
... @SethCarnegie Erase-remove with a lambda for the predicate elegantly allows that (since this is already C++11)
– Potatoswatter
Apr 28 '12 at 23:13
11
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How to get CRON to call in the correct PATHs
I'm trying to get cron to call in the correct PATHs. When I run a Python script from shell the script runs fine as it uses the PATHs set in bashrc but when I use cron all the PATHs are not used from bashrc. Is there a file I can enter the PATHs into for cron like bashrc or a way to call the PATHs fr...