boolean

来源： https://stackoverflow.com/questions/63593458/boolean-variable-within-generator

问题 In C how much space does a bool (boolean) take up? Is it 1 bit, 1 byte or something else? Does it matter if the program is 32-bit or 64-bit? 回答1: If you are referring to C99 _Bool try: printf("%zu\n", sizeof(_Bool)); /* Typically 1. */ Note the standard says: 6.2.5 An object declared as type _Bool is large enough to store the values 0 and 1. The size cannot be smaller than one byte. But it would be legal to be larger than one byte. 回答2: The smallest addressable "thing" in C is a char . Every

问题 I have spent the last 5 hours searching for an answer. Even though I have found many answers they have not helped in any way. What I am basically looking for is a mathematical, arithmetic only representation of the bitwise XOR operator for any 32bit unsigned integers. Even though this sounds really simple, nobody (at least it seems so) has managed to find an answer to this question. I hope we can brainstorm, and find a solution together. Thanks. 回答1: XOR any numerical input a + b - ab(1 + a +

问题 Consider the following example: $a='This is a test'; If I now do: if(strpos($a,'is a') !== false) { echo 'True'; } It get: True However, if I use if(strpos($a,'is a') === true) { echo 'True'; } I get nothing. Why is !==false not ===true in this context I checked the PHP docs on strpos() but did not find any explanation on this. 回答1: Because strpos() never returns true: Returns the position of where the needle exists relative to the beginning of the haystack string (independent of offset).

问题 I have run into a property which I find peculiar about resampling Booleans in pandas . Here is some time series data: import pandas as pd import numpy as np dr = pd.date_range('01-01-2020 5:00', periods=10, freq='H') df = pd.DataFrame({'Bools':[True,True,False,False,False,True,True,np.nan,np.nan,False], "Nums":range(10)}, index=dr) So the data look like: Bools Nums 2020-01-01 05:00:00 True 0 2020-01-01 06:00:00 True 1 2020-01-01 07:00:00 False 2 2020-01-01 08:00:00 False 3 2020-01-01 09:00:00

问题 I have run into a property which I find peculiar about resampling Booleans in pandas . Here is some time series data: import pandas as pd import numpy as np dr = pd.date_range('01-01-2020 5:00', periods=10, freq='H') df = pd.DataFrame({'Bools':[True,True,False,False,False,True,True,np.nan,np.nan,False], "Nums":range(10)}, index=dr) So the data look like: Bools Nums 2020-01-01 05:00:00 True 0 2020-01-01 06:00:00 True 1 2020-01-01 07:00:00 False 2 2020-01-01 08:00:00 False 3 2020-01-01 09:00:00

问题 I have to add user data into database table named "employees". It has ID, Name, LastName,UserName, Password, E-mail, address, administrator_rights options. Administator_rigts is bool option (yes or no). How do i do that, when i make a form that has all the data, and i want to check if user has administrator rights by checkbox (checked - true , unchecked - false). This is my statement which doesn't include admin_rights because i dunno how to do it. Please help me out string write = "Insert

问题 How big (in bits ) is a Windows BOOL data type? Microsoft defines the BOOL data type as: BOOL Boolean variable (should be TRUE or FALSE). This type is declared in WinDef.h as follows: typedef int BOOL; Which converts my question into: How big (in bits) is an int data type? Edit: In before K&R. Edit 2: Something to think about Pretend we're creating a typed programming language, and compiler. You have a type that represents something logically being True or False . If your compiler can also

问题 This question already has answers here : Boolean variable returns as string from javascript function [duplicate] (2 answers) All falsey values in JavaScript (4 answers) Closed 17 days ago . So i just started learning javascript, I'm in the functions module now and I was playing around with it and suddenly i ran into a doubt: why is this: if(x==true){ return 1; } different from this: if(x){ return 1; } ? You see, i have this code: function isAdult(age){ if(age >= 18){ return true; } return

问题 This question already has answers here : Boolean variable returns as string from javascript function [duplicate] (2 answers) All falsey values in JavaScript (4 answers) Closed 17 days ago . So i just started learning javascript, I'm in the functions module now and I was playing around with it and suddenly i ran into a doubt: why is this: if(x==true){ return 1; } different from this: if(x){ return 1; } ? You see, i have this code: function isAdult(age){ if(age >= 18){ return true; } return