JavaScript in the application process will encounter a variety of comparisons, today to all of you to organize three kinds of situation, together to learn.
1. Comparison of two objects
JavaScript comparisons are mixed with some of the more bizarre features, so let's take a look at some simple comparisons.
Comparison of original values
> var a =
undefined
> var b =
undefined
> A = = B
true
> A = =
Original: http://apps.hi.baidu.com/share/detail/31263915
Comparison of strings and values in the shell
In the shell, the comparison between the string and the numerical method is different, pay attention to distinguish
Integer comparison:
-eq equals, such as: if ["$a"-eq "$b"]
-ne not equal to, such as: if ["$a"-ne "$b"]
-GT greater than, such as: if ["$a"-
In the previous article we introduced the file comparison tool commands, followed by the last introduction:
Third, the Operation guide
1. Interface function:
The operation instruction mainly is to introduce the function of each menu item of the interface. So first of all to familiarize yourself with the appearance of the WinDiff, no matter which one you use, open the following interface as shown in the picture:
File menu:
Compare files (file
There is a basic concept in JS:JavaScript in Undefined==nullBut Undefined!==nullUndefined and Null are converted to Boolean values are falseIf you follow a general idea, such as the following codevar a=1; alert (Boolean (a)); // returns True // then the following code should also return Truealert (1==true); // But for sure, the following code will return Falsealert (1===true);But for the following code, it is estimated that most JS programmers will wonder alert (123==true ); // why return false
As you know, the map at the bottom of the STL is implemented with a red-black tree, and its generic prototype is as follows:
Template
Where _key represents a comparison of the key (key), _TP represents the value, _compare represents a comparison, _alloc represents the memory allocator.
In general, when we write a map, we are always like writing the following code:
Map
Indicates that the key is an int typ
This article mainly introduces the usage of php character comparison functions similar_text, strnatcmp, and strcasecmp, and analyzes in detail the usage of these three string comparison functions in the form of examples, which is of great practical value, for more information about the usage of php character comparison functions similar_text, strnatcmp, and strca
Type comparison:
When comparing objects, it is often necessary to know their types in order to determine whether a comparison of values can be made.
Method one.
You can use the GetType () method with the typeof () operator to determine the type of the object.
Example: int i = ten; if (i.gettype () = = typeof (Int32)) { Response.Write ("Type of Int32"); }Method
If you compare a number with a string or a string that involves the content of a number, the string is converted to a value and compared to a value. This rule also applies to switch statements. When used or! During the comparison, no type conversion is performed because the types and values must be compared. Comparison operators, as their names imply, allow comparison
Millet 5s and Oppo R9 which good millet 5s and oppo R9 difference contrast
First of all, briefly introduce the Millet 5s and Oppo R9
Millet 5s is the September 27, 2016 millet autumn new product launch of a flagship mobile phone, the main hole-free ultrasonic fingerprint identification, ultra-sensitive camera, Gaotong 821 high-end configuration, in addition to the high version also equipped with 3D touch-sensitive screen function, the price of 1999 yuan.
Millet 5s B
1.qsort function:Primitive : void qsort (void *base, int nelem, int width, int (*fcmp) (const void *,const void *)); power : sorting using a quick sort routineParameters1 array first address to sort2 number of elements to be sorted in the array3 space size of each element4 A pointer to a function that determines the order of the sort stating that :the Qsort function is provided in the ANSI C standard, and its declaration in the Stdlib.h file is written according to the dichotomy, with a time c
Table 1. PHP comparison Operators
Example name result$a = = $b equals TRUE If the $a equals $b.$a = = = $b congruent TRUE if $a equals $b, and they are of the same type. (introduced in PHP 4)$a! = $b unequal to TRUE if $a is not equal to $b.$a $a!== $b non-congruent TRUE if $a are not equal to $b, or they are of different types. (PHP 4 only)$a $a > $b is greater than TRUE if $a strictly $b.$a $a >= $b is greater than or equal to TRUE if $a is greater
How does php compare queries? I don't know how to add comparison queries. if other parts are done well, I just don't know how to add comparison queries. how can I add them to databases? Need to insert a database? ------ Solution -------------------- should there be a comparison strategy? If you want to use a database, check whether you need to save the
I read the article "Comparison of Java and PHP in Web development" published by a netizen, and I also expressed my opinion.
I. Language Comparison
PHP is really easy to learn. It can be simply encoded in the process mode without having to understand the concept of any class. You can see the discuz code. Make good use of include.
PHP also has classes, but unlike Java, PHP attributes are relatively free, wh
What are the differences between PHP and ASP. NET? What is the necessity for comparing PHP with ASP. NET? This article will give you an answer.
PHP and ASP. net comparison, whether you have selected PHP or not, according to its performance in the following table on price, speed, efficiency, security, platform support, and open source or not, we can all tell that its strength is far better than its weakness. The only disadvantage is the lack of ob
logic.1.2 MyBatis IntroductionThe focus of IBATIS is the mapping relationship between Pojo and SQL. The parameters that SQL requires and the returned result fields are then mapped to the specified Pojo by mapping the configuration file. IBATIS is an ORM implementation of "SQL Mapping" relative to Hibernate "O/R". Chapter II development comparison Development SpeedHibernate's real mastery is more difficult than mybatis. The MyBatis framework is relati
I. GENERAL class of OperatorsAll operator types are enumerated first: arithmetic operators, assignment operators, comparison operators, logical operators, bitwise operators, and ternary operators.What is named operator, which is called operator, is it a symbolic representation of the operation? you can see some of the original books in English.This section discusses comparison operators and logical operator
Objective: To grasp the classification of sorting algorithm and the comparison of different algorithm complexity, to make sure that xxx is independent of the initial state of the array is divided into several situations:A, the algorithm complexity is independent of the initial state;b, the total number of elements compared to the initial state independent;C, the total number of elements moved is independent of the initial state.1. Algorithm classifica
and any number do operations equal to Nan, while using the subtraction operator also pay attention to the problem of decimals;Addition operatorAddition operator can be said to be the most used in the development of an operator, is also more complex, its operational rules and multiplicative operators and subtraction operators are not the same;There are two ways to use the addition operator:
two numbers added;
two concatenation of strings;
If both are numeric types or
current min, and if so, whether or not the position of the two subscript corresponding element is exchanged if it is inconsistent.The following is a combination of this sentence to do an analysis:First trip: Before comparing, define the subscript that Min uses to hold the current smallest element.A[min] respectively and A[i+1] (A[j]) comparison, the first a[0](5) and A[1](7) comparison, a[0] small, continu
Since we are comparing today's soft routing and hardware wide-band routers to the use of broadband access, we need to place the primary comparisons in these areas. So clear that we can have some sober views on the comparison.
We divide the functional comparison into the essential function and the rating function as a comparison. The so-called necessary function
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.