javascript string concatenation operator

JavaScript Introduction: JavaScript is a scripting language that belongs to the web! JavaScript is used by millions of of pages to improve design, validate forms, detect browsers, create cookies, and apply more. JavaScript is the most popular scripting language on the Internet. The following focuses on the composit

...... 0 Php Operator Precedence associativity Operators Additional Information Non-associative Clone new Clone andnew Left [ Array () Right ** Arithmetic Right + +--~ (int) (float) (string) (array) (object) (BOOL) @ Types Andincrement/decrement Non-associative in

Reprint: https://www.cnblogs.com/weiqinl/p/9049745.htmlThere are two ways to compare JavaScript: the strict comparison operator and the conversion type comparison operator.Corresponds === , and, in the equality operator !== == != .Give me a chestnut first.var str=' 1 'var NUM0=0var num1=1var BlT=Truevar BlF=Falsevar nul=NullVar und=UndefinedConsole.Log (str= = NU

Javascript is a magic language, but there is no magic plus operator in it. Common addition operators can be used: 1. addition operation, for example: alert (1 + 2) ;=> 32. String connection, for example, alert ("a" + "B"); => "AB" "+ =" Is also advanced, and the above two operations are also done. Yesterday, I asked a question in the

operands of the typeof operator can be either a variable (message) or a numeric literal. Note that TypeOf is an operator, not a function, so the parentheses in the example are not necessary (although they can be used).From the above example, we find that the numbers created with number () are also returned with the value "Object" by TypeOf, because the constructor returns objects, so if we want to differen

); The "function" nbsp; nbsp; examples show that the operands of the typeof operator can be either a variable (message) or a literal number. Note that TypeOf is an operator rather than a function, so the parentheses in the example are not required (although they can be used). nbsp; nbsp; From the above example, we found that numbers created with number () are also returned with the value "Object" by TypeOf,

);Typeof (Date );Typeof (sss );Typeof (undefined );What are you going to do?If you do not quite understand it after reading it, see the following (people who understand it do not need to read it ):Typeof is a unary operator. It returns a string and returns different results for different operands.The specific rules are as follows:1. For numeric operands, the value returned by typeof is number. For example,

Recently to do data processing, custom some of the structure, such as mat,vector,point, for subtraction, such as arithmetic to repeat the definition, the code is not very intuitive, JavaScript does not have operator overloading this kind of functions like C + +, C # is really unpleasant, So think "curve salvation", automatic translation code to implement operator

determines the result, the second operand is no longer counted. For a logical AND operation, if the first operand is false, the result cannot be equal to true regardless of the value of the second operand.Consider the following example: var btrue = true; var bresult = (btrue bunknown); Error alert (bresult) occurred;//This line will not execute Code Run Results: This code throws an error when doing a logical and operation, because the variable bunknown is undefined. The value

on any type of data and convert it to the corresponding Boolean value.Undefined:falseNull:falseBoolean: Is the value of itselfNumber: Except that 0 thought it was true.String: Except for the empty string, I think it's true.Object: True2. Assigning values to class variablesvar a = b cIf one operand is an object and the other is a Boolean value, the object is returned.If the two operands are objects, the second object is returned.Returns null if one o

typeof operatorReturns a string that is used to represent the data type of an expression. typeof[() expression[]]; The expression parameter is any expression that needs to find the type information. DescriptionThe typeof operator returns the type information as a string. There are six possible typeof return values: "Number," "