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Why is lazy evaluation useful?
...ges let you reason about function definitions using equational reasoning.
foo x = x + 3
Unfortunately in a non-lazy setting, more statements fail to return than in a lazy setting, so this is less useful in languages like ML. But in a lazy language you can safely reason about equality.
Secondly, ...
compareTo() vs. equals()
...
A difference is that "foo".equals((String)null) returns false while "foo".compareTo((String)null) == 0 throws a NullPointerException. So they are not always interchangeable even for Strings.
...
What is an example of the simplest possible Socket.io example?
...id sent from the server
socket.emit('i am client', {data: 'foo!', id: data.id});
});
socket.on('time', function(data) {
addMessage(data.time);
});
socket.on('error', console.error.bind(console));
socket.on('m...
How can I determine the current line number in JavaScript?
...some marks.
Here is a quick example (yes, it's messed a little).
function foo()
{
alert(line(1));
var a;
var b;
alert(line(2));
}
foo();
function line(mark)
{
var token = 'line\\(' + mark + '\\)';
var m = line.caller.toString().match(
new Re...
How do you check in python whether a string contains only numbers?
... I had no idea that method existed. I've always done try: assert str(int(foo)) == foo; except (AssertionError,ValueError): #handle and it felt ugly as sin. Thanks!
– Adam Smith
Jan 27 '14 at 18:23
...
What is the difference between Gemfile and Gemfile.lock in Ruby on Rails
...last digit in the used gem can be "greater than" the given version. E.g., foo ~> a.b.c.d means any version of foo is fine as long as it's still a.b.c.{something} where {something} >= d. See also related question
– michael
Feb 10 '13 at 0:32
...
jQuery get value of select onChange
...ith script you need to pass a reference to the current element:
onselect="foo(this);"
and then:
function foo(element) {
// $(element).val() will give you what you are looking for
}
share
|
...
Is there a performance difference between i++ and ++i in C?
...uld indeed be slower since with ++it you can just return the final value.
Foo Foo::operator++()
{
Foo oldFoo = *this; // copy existing value - could be slow
// yadda yadda, do increment
return oldFoo;
}
Another difference is that with ++i you have the option of returning a reference instead...
Why does cURL return error “(23) Failed writing body”?
...ious program is finished writing the whole page.
In curl "url" | grep -qs foo, as soon as grep has what it wants it will close the read stream from curl. cURL doesn't expect this and emits the "Failed writing body" error.
A workaround is to pipe the stream through an intermediary program that alwa...
How can I print variable and string on same line in Python?
...print statement separates the items by a single space:
>>> print "foo","bar","spam"
foo bar spam
or better use string formatting:
print "If there was a birth every 7 seconds, there would be: {} births".format(births)
String formatting is much more powerful and allows you to do some other ...