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: This article mainly introduces the relationship between 0, null, empty, and false in PHP empty strings. For more information about PHP tutorials, see. // Determine the relationship between 0 and '', null, empty, and false $ A = 0; Echo

The PHP empty string describes the relationship between 0, null, empty, and false. If the method function is used incorrectly or is used less, if the logic sequence of several method functions is wrong, it may be a vulnerability and cannot be found

Determine the relationship between 0 and ', null, empty, False $a = 0; The relationship between echo "0 and", empty, NULL, false: "; if ($a = = ") { echo "0 = ="; "; }else{ echo "0! ="; "; } if (trim ($a) = = ") { echo "Trim (0) = ="; "; }else{ echo

Php 0, null, empty, null, false, detailed description of the string relationship. I encountered a strange problem in a project, and it took me a lot of time to solve it. The final debugging found that it was a judgment problem-about 0 and ''(null

In a project encountered a strange problem, it cost me a lot of time is not resolved, the final debugging found is the question of judgment-about 0 and "(empty single quotation marks, for good see I added a space), I found 0==" incredibly set up,

I encountered a strange problem in a project, and it took me a lot of time to solve it. The final debugging found that it was a judgment problem-about 0 and ''(null single quotes, for better understanding, I added a space), I found that 0 = "was

I encountered a strange problem in a project, and it took me a lot of time to solve it. The final debugging found that it was a judgment problem-about 0 and ''(null single quotes, for better understanding, I added a space), I found that 0 = "was

0, "" (empty string), null, empty, and the difference with nothingAnswer the following questions first! After the following descriptions, variables A, B, C, and D are equal to 0,"", Null, empty, and nothing?DimDim B as stringDim C as integerDim D as

Encountered a strange problem in a project that cost me a lot of time without solving final debugging discovery is the question of judgment--about 0 and ' (empty single quotes, for good see I add a space) judgment, I found 0== "incredibly set up,

Today do information collection page encountered a strange problem, study for a long time to find the root cause of the problem, it is a bit strange indeed.(the younger brother often uses the C #, Java and other languages, PHP only occasionally in

null: Is an object, but a null reference (not pointing to any object)Empty Object : is an object, but its value is a reference to an object that does not have any propertiesundefined: Undefined, so not an object, which itself is defined as a special

In-depth understanding of the relationship between 0, null, empty, null, false, and strings in php // Judge the relationship between 0 and ''and empty null false. start // If ('safdasefasefasf' = 0 ){

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

Source: Empty object (NULL), null (empty), space in Java about stringDefinedEmpty object:String s = null;An empty object is defined as an object s, but no space is allocated to the object, i.e.the object is not instantiated, therefore, the empty

";//2. Variable $ A etc 0 not true if ($a) {echo $a;} Else{echo "unequal to 0";} echo "";//3.empty-checks if a variable is empty/* If VAR is a non-null or nonzero value, empty () returns FALSE. In other words, "", 0, "0", NULL, FALSE, Array (), Var $

When Beanutils.copyproperties is used, the null value is also copied to make it a very chicken side.He is extended to support a variety of null values are no longer copied Public Abstract classBeanutilsextendsOrg.springframework.beans.BeanUtils {

In this paper, we introduce the sources and methods of null,empty,nothing of these kinds of null values in ASP. Dim ADim B as StringDim C as IntegerDim D as Object A is equal to Empty because the "unshaped variable" that has not yet been

Today do information collection page encountered a strange problem, study for a long time to find the root cause of the problem, it is a bit strange indeed. (the younger brother often uses the C #, Java and other languages, PHP only occasionally in

Null (NULL): A special data type in PHP that represents a null value, which means that no value is set for the variable null (null value) is case-insensitive, and null and NULL are the same. There are three possible cases where a null value is

Determine the relationship between 0 and ' ' and empty null false start// if (' safdasefasefasf ' ==0) { echo "The string is converted to a number equal to 0"; }//output: The string is converted to a number equal to zero. This is