大约有 37,000 项符合查询结果（耗时：0.0605秒） [XML]
All falsey values in JavaScript
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Falsey values in JavaScript
false
Zero of Number type: 0 and also -0, 0.0, and hex form 0x0 (thanks RBT)
Zero of BigInt type: 0n and -0n (new in 2020, thanks GetMeARemoteJob)
"", '' and `` - strings of length 0
null
undefined
NaN
document.all (in HTML browsers only)
This is a ...
How to get first character of string?
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1080
What you want is charAt.
var x = 'some string';
alert(x.charAt(0)); // alerts 's'
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What is the >>>= operator in C?
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The line:
while( a[ 0xFULL?'\0':-1:>>>=a<:!!0X.1P1 ] )
contains the digraphs :> and <:, which translate to ] and [ respectively, so it's equivalent to:
while( a[ 0xFULL?'\0':-1 ] >>= a[ !!0X.1P1 ] )
The literal 0xFUL...
Java String - See if a string contains only numbers and not letters
...Z]+") == false && text.length() > 2){
to:
if (text.matches("[0-9]+") && text.length() > 2) {
Instead of checking that the string doesn't contain alphabetic characters, check to be sure it contains only numerics.
If you actually want to use the numeric value, use Integer.p...
How can I map True/False to 1/0 in a Pandas DataFrame?
... that has boolean True/False values, but for further calculations I need 1/0 representation. Is there a quick pandas/numpy way to do that?
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Why is address zero used for the null pointer?
...s a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid, etc.
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How to generate keyboard events in Python?
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+50
It can be done using ctypes:
import ctypes
from ctypes import wintypes
import time
user32 = ctypes.WinDLL('user32', use_last_error=T...
Are members of a C++ struct initialized to 0 by default?
... constructors
struct Snapshot {
int x;
double y;
Snapshot():x(0),y(0) { }
// other ctors / functions...
};
Will initialize both x and y to 0. Note that you can use x(), y() to initialize them disregarding of their type: That's then value initialization, and usually yields a proper...
Warning: Found conflicts between different versions of the same dependent assembly
I am currently developing a .NET application, which consists of 20 projects. Some of those projects are compiled using .NET 3.5, some others are still .NET 2.0 projects (so far no problem).
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Cocoa: What's the difference between the frame and the bounds?
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908
The bounds of an UIView is the rectangle, expressed as a location (x,y) and size (width,height)...