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What is the difference between “ is None ” and “ ==None ”
...o quote:
A class is free to implement
comparison any way it chooses, and it
can choose to make comparison against
None mean something (which actually
makes sense; if someone told you to
implement the None object from
scratch, how else would you get it to
compare True against itself...
How to split a String by space
...
I find it useful as my use case was to split the string and remove multiple spaces. One line of code does both for me.
– Niharika Upadhyay
Jul 10 '18 at 9:06
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Pointer arithmetic for void pointer in C
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Final conclusion: arithmetic on a void* is illegal in both C and C++.
GCC allows it as an extension, see Arithmetic on void- and Function-Pointers (note that this section is part of the "C Extensions" chapter of the manual). Clang and ICC likely allow void* arithmetic for the purpose...
MongoDB.Driver.MongoConnectionException: Unable to connect to the prim...
MongoDB.Driver.MongoConnectionException: Unable to connect to the primary member of the replica set: Too many threads are already waiting for a connection..
C# Driver:1.3.1
Replset:
localhost:10001 (primary)
localhost:10002 (member)
I have initReplset and add localhost:10002 to the replse...
PHP学习必看的一些书 - PHP - 清泛IT论坛，有思想、有深度
对应初学的PHP，应该买什么样的书？到处问人，到处求助？ 该文章列举了一些书籍，感觉还行，特此重新整理了一下。觉得有些言过其实了，或者是没必要去看的。
该书单我经过一些调整。PHP相关《PHP程序设计》(第2版) –PHP...
App Inventor 2 Encrypt.Security 安全性扩展：MD5哈希，SHA/AES/RSA/BASE6...
这是关于App Inventor和Thunkable安全性的扩展，它提供MD5哈希，SHA1和SHA256哈希，AES加密/解密，RSA加密/解密，BASE64编码/解码方法。权限此扩展程序不需要任何权限。事件OnErrorOccured抛出任何异常时将触发此事件。此事件中有两个变...
BLE UUID是对的但连接闪退：java.lang.IllegalArgumentException: UUID str...
请问UUID是对的 连接闪退，
下面是报错日志
java.lang.ExceptionInInitializerError
at edu.mit.appinventor.ble.BluetoothLEint$BLEReadOperation.subscribe(BluetoothLEint.java:357)
at edu.mit.appinventor.ble.BluetoothLEint$BLEReadOperation.run(BluetoothLEint.java:325)
at android.os....
Invoke: no method named `…………’ in class java.lang.Boolean - App I...
可能原因1：可能是因为使用了“计时器”组件，而它一直在计时，且触发计时任务导致的。删除不再使用的计时器组件即可解决。
I've deleted the "clock" which was not even in the blocks present...and it works... Maybe it helps someone.
来自...
BLE数据收发 20个字节的限制问题 - 创客硬件开发 - 清泛IT社区，为创新赋能！
请问BLE插件只支持20个字节的数据接收与发送吗，我尝试超过20个字节就会自动忽略掉后面的字节RequestMTU – 为 BluetoothLE 连接请求新的最大传输单元 (MTU)。此功能仅在两个设备都支持蓝牙 4.2 或更高版本时才受支持。如果 MTU 更改...
蓝牙接收的数据怎么一行一行更新显示和，类似图2这样的 - App应用开发 - 清...
在做BLE蓝牙显示app。蓝牙端一个数据一个数据的发送，但是显示的时候后一个会覆盖上一个 无法将接收的数据全部罗列出来，而且显示的还有问题，有时候显示一个，有时候显示3个数据。求解！！使用列表显示框组件，详见文...