At work we are constantly writing code, writing JavaScript, very little time for conceptual research. I have nothing to do today, I studied the relationship between "null" and "0". I hope you have seen the end of the harvest.
Alert (null>=0)
What
First look at a special case:
Var_dump (0 = = ' false '), returns BOOL (true), PHP determines 0 equals any string, Var_dump (0=== ' false '), returns BOOL (false), and the congruent contains type and value to be equal.
Var_dump (0 = false),
Http://blog.chinaunix.net/uid-28458801-id-3941112.htmlThe difference between false/true and False/true 1. The difference between false/true and false/true: False/true is a new keyword in the standard C + + language, and False/true is through #
JavaScript you don't Know (middle)--ToBooleanThe values in JavaScript can be divided into the following two categories:1. A value that can be coerced into a type that is False2. Other (values that are cast to true for the coercion type)false Values -
Turn from:insertable = false, updatable = False useWhen using JPA to configure an entity, if there are two attributes (one is a generic attribute and one is a many-to-one property), the error will be indicated when mapping to the same column in the
In PHP because it is a weakly typed language, the different types of values can be implicitly converted, making false,null, ", 0, ' 0′ The comparison of these values is somewhat confusing, now summarizes:Equal judgment' = = NULL = = 0 = = False
AspNetPager is an instance of comparison between true and false pages, and aspnetpager is a real and false page.
It has been a while since learning BS. BS is designed for Web pages, including the data retrieved from the database and displayed on the
Generally, the entire training set is divided into two parts: the appointment of data60-80%Put it into our training set to generate the model; then put the rest of the data into a test set, and immediately use it to test the accuracy of our
These concepts were known a long time ago, but they are often forgotten because they are not the same as their cognitive habits. So simply to summarize these concepts, and then forget to look for (other articles too verbose, computational methods
For example, the following code:
$str4="php-class,mysql-class,div-css,0,dreamweaver";$s=strtok($str4,',');while($s!==false){ echo $s.""; $s=strtok(',');}
while ($s ===true) {} Why can't it be displayed?True where to use it ~ ~Beginners Please
Recall (recall rate); Precision (accuracy rate); F1-meature (Comprehensive evaluation index); These parameters are often used in information retrieval (such as search engines), natural language processing, and detection classifications.Precision:
See the table below.
True positive ---- the prediction is correct and positive;
True negative --- the prediction is correct and negative;
False Positive --- incorrect prediction. Positive prediction. (positive prediction is false)
False
As we all know, for the traditional anti-virus software which relies mainly on the virus signature library, the omission is an important drawback which cannot be overcome. For the past, the number of viruses is relatively small, the network is not
This article introduces several examples of the differences between daemon attribute values in Python multi-threading.Review:The previous article briefly describes the modern operating system in which each process considers itself exclusive of all
When releasing a website, set debug to false and release debug to false.
Under the root directory of the ASP. NET projectWeb.configThere is such a node:
You can set it in this way during the development phase. After deploying a website on the
The empty () function is used to determine whether a string is empty
As long as the variable is 0,null, ", False,empty () is judged to be true.
$num 1= '; $num 2=0; echo $num 1== $num 2; Echo ''; echo $num 1=== $num 2? ' 1 ': ' 0
The setupdienumdeviceinterfaces function enumerates the device interfaces that is contained in a device Informat Ion set.BOOL setupdienumdeviceinterfaces ( _in_ hdevinfo deviceinfoset, _in_opt_ psp_devinfo_data DeviceInfoData,
_in_ Const GUID
Preface: Or I, a naively small white, risking his life to the company of a forced lattice interview, go to interview on the way to experience some twists and turns, the bus death not come, finally almost missed the interview time, this is not what,
File_put_contents execution returns false,file_put_contents false (Linux server httpd)By default, SELinux is turned onTo view the SELinux status:1,/usr/sbin/sestatus-v # #如果SELinux The status parameter is enabled is turned onSELinux status:enabled2.
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