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Empty set literal?
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By all means, please use set() to create an empty set.
But, if you want to impress people, tell them that you can create an empty set using literals and * with Python >= 3.5 (see PEP 448) by doing:
>>> s = {*()} # or {*{}} or {*[]}
>>> print(s)
set()
this is b...
Pad a string with leading zeros so it's 3 characters long in SQL Server 2008
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If the field is already a string, this will work
SELECT RIGHT('000'+ISNULL(field,''),3)
If you want nulls to show as '000'
It might be an integer -- then you would want
SELECT RIGHT('000'+CAST(field AS VARCHAR(3)),3)
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How can I check whether an array is null / empty?
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There's a key difference between a null array and an empty array. This is a test for null.
int arr[] = null;
if (arr == null) {
System.out.println("array is null");
}
"Empty" here has no official meaning. I'm choosing to define empty a...
Fastest way to check if a string matches a regexp in ruby?
What is the fastest way to check if a string matches a regular expression in Ruby?
7 Answers
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Ruby - elegantly convert variable to an array if not an array already
... the original use of to_a. For instance, {a: 1, b: 2}.each ... would work differently.
– sawa
Aug 21 '13 at 14:15
1
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Which UUID version to use?
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There are two different ways of generating a UUID.
If you just need a unique ID, you want a version 1 or version 4.
Version 1: This generates a unique ID based on a network card MAC address and a timer. These IDs are easy to predict (giv...
Determine Whether Integer Is Between Two Other Integers?
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if 10000 <= number <= 30000:
pass
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栈和队列的面试题Java实现 - 更多技术 - 清泛网 - 专注C/C++及内核技术
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//方法：入栈操作
public void push(int data) {
if (head == null) {
head = new Node(data);
current = head;
} else {
Node node = new Node(data);
node.pre = current;//current结点将作为当前结点的前驱结...
How to determine if a number is odd in JavaScript
Can anyone point me to some code to determine if a number in JavaScript is even or odd?
27 Answers
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Check if option is selected with jQuery, if not select a default
Using jQuery, how do you check if there is an option selected in a select menu, and if not, assign one of the options as selected.
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