javascript catch syntax error

First, Introduction1. JavaScript What is it, a thing? It is a scripting language and requires a host file whose host file is an HTML file.2 , it and Java What's the matter? There is no direct connection, Java is Sun (No, has been acquired by Oracle), JavaScript is Netscape (Netscape has not, was bought by AOL), JScript is Microsoft, 90% like JavaScript, Some feat

categories: primitive type and composition type, Brendan eich think that the value of "none" is best not an object.Second, the initial version of JavaScript does not include the error handling mechanism, when data type mismatch occurs, is often the type of automatic conversion or silently fail. Brendan Eich felt that if the null automatic switch to 0, it is not easy to find errors.Therefore, Brendan Eich a

onfocusLost Focus Event OnblurMouse over Event onmouseoverMouse Move Event onmouseoutThe onsubmit event occurs when the confirmation button in the form is Clicked.this.children;The ParentNode property returns the parent node of the specified Node.The parsefloat () function resolves a string and returns a floating-point number.The ChildNodes property returns a collection of child nodes of the node to NodeList the Object.The content from the starting position to the terminating position, but it r

() {return "1";}, function g () {return 2;})();typeof F; A. "string" B. "number" C. "function" D. "Undefined"09.var x = 1;if (function f () {}) {x + = typeof F;} X; A. 1 B. "1function" C. "1undefined" D. NaNAnswer: C10.var x = [typeof x, typeof y][1];typeof typeof X; A. "Number" B. "string" C. "Undefined" D. "Object"Answer: B11.(function (foo) {return typeof foo.bar;}) ({foo: {bar:1}}); A, "undefined" B, "Object" C, "number" D, ErrorAnswer: A12.(Functionf () {function f () { return1;} returnf (

declaration","Redefinition of ' {a} '.": "' {a} ' is defined repeatedly","It isn't necessary to initialize ' {a} ' to ' undefined '.": "No need to initialize ' {a} ' to ' undefined '","Expected a conditional expression and instead saw an assignment.": "Here you need an expression, not an assignment statement","Expected a ' break ' statement before ' case '": "Need to have ' break ' before ' case '.","Expected a ' break ' statement before ' default '.": "You need to have ' break ' before ' defau

(the variable name is an identifier).The so-called variable is the amount that can be changed again after initialization.ECMAScript is a weakly typed (loosely typed) language that can change the amount of different types at the same time. (but this is difficult for later maintenance, and performance is not high, resulting in high costs!) )var box = "java"= +; alert (box);2. Considerations for Defining variables:This statement defines the box variable, but does not initialize it (that is, it doe

Original: JavaScript syntax details--Reference and copyWe all know, JS in the variable assignment there are two ways, recently in the toss themselves to write the tab bar plug-in, encountered a lot of problems usually not noticed. Well, that's clear over there, a little tidying up on the reference and replication-related knowledge, may occasionally add new problems, there are mistakes want to see the person

supports strict mode includes ie10+, firefox4+, safari12+, opera12+, Chrome"keywords and reserved Words"[1] KeywordsBreak | do| Instanceof| typeof | Case | else | New | var | Catch | Finally | return | void | Continue | for | *switch | While | function | This | with | Default | If | throw | Delete | In | Try | debugger*[2] Reserved wordsAbstract | enum | int | Short | Boolean | Export | interface | static | byte | Extends | Long | Super | char | *fin

function is to pop up a dialog box that allows you to enter content. For example: Prompt ("Enter a number in the bar", "can only be a number Oh");=================================================================================================JS Syntax:1. Basic Data type: string, Decimal, Integer, Time Date, Boolean, etc.2, variables: All types of variables are defined by VAR.3, type conversion: automatic conversion and casting, generally with cast.

JavaScript-basic syntax (4)Global method and Number objectDemonstrate global method and Number Alert (parseInt ("123" + 1); outln (parseInt ("abc"); // NaN, invalid var val = parseInt ("abc "); outln ("value =" + isNaN (val); // isNaN determines if it is illegal var val2 = parseInt ("123 afsa"); // val2 = 123 outln (val2 ); // It should be noted that if the parameter starts with a number, the parseInt metho

Syntax errors, also known as parsing errors, occur in the compilation of traditional languages, occur in the interpretation of JavaScript, and runtime errors are also known as exceptions (exception, after the interpreter during compilation) I. Error Classification 1. syntax error