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How to check if a map contains a key in Go?
...
One line answer:
if val, ok := dict["foo"]; ok {
//do something here
}
Explanation:
if statements in Go can include both a condition and an initialization statement. The example above uses both:
initializes two variables - val will receive either the va...
How to create a directory using Ansible
...ound that it changes child files permissions also... almost like mkdir -p /foo/bar && chmod -R 0775 /foo/bar.. has anyone else observed this with Ansible 2.0.0.2
– ThePracticalOne
May 11 '16 at 14:04
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What is a NullReferenceException, and how do I fix it?
...bers (such as methods) through a null reference. The simplest case:
string foo = null;
foo.ToUpper();
This will throw a NullReferenceException at the second line because you can't call the instance method ToUpper() on a string reference pointing to null.
Debugging
How do you find the source of a Nu...
Access parent URL from iframe
...ggestion. For those who are writing the parent html iframe code this would foot the bill. We used something very similar in our pixel software.
– Ligemer
Nov 25 '14 at 0:30
...
When is del useful in python?
...ly, using del on a local variable makes the intent clearer. Compare:
del foo
to
foo = None
I know in the case of del foo that the intent is to remove the variable from scope. It's not clear that foo = None is doing that. If somebody just assigned foo = None I might think it was dead code. But...
How do I get jQuery to select elements with a . (period) in their ID?
...id selector if the id contains spaces. Use an attribute selector:
$('[id=foo bar]').show();
If possible, specify element type as well:
$('div[id=foo bar]').show();
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How do I remove a property from a JavaScript object?
... delete operator is used to remove properties from objects.
const obj = { foo: "bar" }
delete obj.foo
obj.hasOwnProperty("foo") // false
Note that, for arrays, this is not the same as removing an element. To remove an element from an array, use Array#splice or Array#pop. For example:
arr // [0, ...
Mockito - difference between doReturn() and when()
...fBoundsException (the list is yet empty)
when(spy.get(0)).thenReturn("foo");
//You have to use doReturn() for stubbing:
doReturn("foo").when(spy).get(0);
2. Overriding a previous exception-stubbing:
when(mock.foo()).thenThrow(new RuntimeException());
//Impossible: the exce...
How to implement “select all” check box in HTML?
...">
function toggle(source) {
checkboxes = document.getElementsByName('foo');
for(var checkbox in checkboxes)
checkbox.checked = source.checked;
}
</script>
<input type="checkbox" onClick="toggle(this)" /> Toggle All<br/>
<input type="checkbox" name="foo" value="bar1...
Ruby class instance variable vs. class variable
...(or rather, a subclass of Class) corresponding to it. (When you say class Foo, you're really declaring a constant Foo and assigning a class object to it.) And every Ruby object can have instance variables, so class objects can have instance variables, too.
The trouble is, instance variables on cla...