equality operator

One, constant 　　 1.1. What is a constantIts value cannot be changed during program execution　　1.2, the classification of the constant　Literal constantsThe contents of a string constant enclosed in double quotation marksinteger constant all

One, Boolean variables 1, false,none,0, "", (), [],{} value is used as a Boolean expression, the interpreter will see the false. All the others are true.2, True==1,false==0.3. The bool function can be used to convert other values.Second, conditional

Connect two arrays; concat to form a new arrayarray 1.concat (array 2, array 1)return value: Arrayvar arr1=[1,2],arr2=[3,4],arr3;arr3=arr1.concat (ARR2,ARR1); Console.log (ARR3);Another way to intercept "is come to be"__.slice (start,end)___.slice

OverviewnullAnd undefined both can mean "no", meaning very similar. Assign a variable to undefined or, to be null honest, the grammatical effect is almost indistinguishable.var a = undefined;// 或者var a = null;In the above code, the a variables are

1, JS basic data type has number, String, number, Null, Undefined, Boolean, there is a complex data type Object,function and array is a derived type of object.2, typeof used to determine the data type of a given variable,"Undefined"-this value is

　　　　　　　　　　　　　　　　　　Chapter fifth conditions, loops and other statements5.1 Print and Import for more information5.1.1 using a comma output>>> print (' age ', 43,45)//You can separate multiple expressions with commas, with spaces in the middleAge 43 45

This document is translated from JavaScript ' s zerosJavaScript has both zeros:? 0 and +0. This post explains, why, and where it matters in practice.There are two "0" in JavaScript:-0 and +0. This article explains why, and points out the impact of

1. To view the contents of a variable, enter it in the console console.log(a); , and the value displayed after carriage return is the contents of the variable.2. Alert (' I don't want to execute '); Prompt box Google browser can be directly executed3

Reference typeA reference type is a data structure that organizes data and functionality together.Reference type: Describes the properties and methods that a class of objects have, and an object is an instance of a particular reference type.1.Object

1.print and Import1.1 Print slightly1.2 Import(1) Impore Somemodule (2) from Somemodule import somefunction(3) from Somemodule import somefunction,anotherfunction(4) from Somemodule import*(5) Import somemodule as Somename #为整个模块提供别名(6) From

Recently participated in a few PHP engineers interview, but the written questions are not ideal, come back to summarize the reasons for failure, is not read the PHP manual. Several companies ' PHP basic interview questions can be found in the PHP

built-in objects in JavaScript1.Array2.String3.Math4.DateArrays in JavaScriptLearning Goals1. Master any array creation2. Mastering the reading and writing of numeric elements3. Mastering the Length property of an array How to create an arrayThere

Object Comparison:Equality: When comparing two object variables using the comparison operator (= =), the principle of comparison is:1. If the properties and property values of the two objects are equal,2. And two objects are instances of the same

In ECMAScript, a reference type is a data structure used to organize data and functionality together, while an object references an instance of a type.Although ECMAScript is technically an object-oriented language, it does not have the basic

14th Operation overloading and type conversion1. You can call the overloaded operator function directly .However, if you have overloaded member functions and overloaded non-member functions for an operator such as +, you will get an error if you use

Read the summary of the knowledge points of JavaScript grammar essenceYesterday to soak up the majority of days of the book Hall, a breath of reading the "JavaScript Grammar essence" of the books, the overall book is still written well, no wonder so

Using operator overloading wisely can make the use of class types as intuitive as built-in types. Overloaded operators must have at least one class type or operand of an enumeration type, which enforces that overloaded operators cannot redefine

Because JavaScript can do flexible type conversions, its "= =" equality operator is also flexible with the meaning of equality. For example, the following comparison results are truenull==undefined //These two values are considered equal to "0" ==0/

In the previous LINQ introduction, we have seen implicit type Var, extension methods (extension method), and lambda expressions. Yes, they are the cornerstone of LINQ technology, they make LINQ implementations possible, and simplify the writing of

ES6 allows you to extract values from arrays and objects in a certain pattern, assigning values to variables, known as deconstructedLet [A, B, c] = [1, 2, 3];The above code indicates that the value can be extracted from the array, and the variable