difference between null and 0

At some point, we need to assign the pointer to a null pointer to prevent the wild pointer. Some people prefer to use NULL as a null pointer constant, for example: int* p = NULL;. There is also a direct use of the 0 value as a null pointer constant,

The difference between 0 and null in php. As a qualified php programmer, some basic knowledge must be known, such as the difference between 0 and null. for this difference, we will perform a simple analysis using several instances, as a qualified

PHP$test=0;if($test= = "'){ Echo' In php, 0 is empty ';//is output}if($test= = = ""){ Echo' In php, 0 is empty ';//not be output}if($test==NULL){ Echo' In php, 0 is empty ';//is output}if($test===NULL){ Echo' In php, 0 is empty ';//not be output}

Difference between 0 and null in PHP: Difference between 0 and null in PHP I do not know that when you store a field with the default data of 0 in the MySQL database, an error occurs when 0 or Null is determined in the program, because 0 and Null

Note: This article refers to the http://blog.csdn.net/mylinx/article/details/6873253 and books "Conquering the C-pointer" ([Day] front bridge and Messiah).The values of NULL, ' + ' and 0 are the same, all 0, but they do not behave the same way:1.

Note: This article refers to the http://blog.csdn.net/mylinx/article/details/6873253 and books "Conquering the C-pointer" ([Day] front bridge and Messiah).The values of NULL, ' + ' and 0 are the same, all 0, but they do not behave the same way:1.

This article mainly introduces the difference between the number 0 and the null value in php, and uses an instance for your convenience. if you need it, you can refer to it as a qualified php programmer, some basic knowledge must be known, for

This article mainly introduces the difference between the number 0 and the null value in php, and uses an instance for your convenience. if you need it, you can refer to it as a qualified php programmer, some basic knowledge must be known, for

Null in the database means "no input data to (column) variables", that is, NULL in the database can distinguish between "no input data to (column) variables" and "Input data to (column) variables". And the input of the empty string, is here the

Next we will introduce you to the difference between Null and 0 values in php, which may be commonly used for fuzzy analysis. here are a few examples. let's take a closer look. The PHP instance code is as follows :? Php $ test0;... the following