javascript problems for beginners

conflict, which is number type and object type (its subclass number type), therefore, instanceof to exclude the types specified in the data types that are already defined, that is, only for custom types.In addition, for arrays with only the concept of class array, there is no array data type, typeof can only return the object data type, so for arrays it is possible to use instanceof.In summary: There is no need to tangle with JavaScript syntax, becau

group object6 7 if(Myarrays = =NULL) {//detect if the cookie has no value8 //set to a spatial array by default9Myarrays =NewArray ();Ten$.cookie ('The_cookieselectfoodorderck','[]', {path:"/", Expires:-1});//Delete Cookies One}Else { A for(vari =0; i ) { - //according to the order type and date - if(myarrays[i].foodate.tostring () = = Foodate.tostring () myarrays[i].foodtype.tostring () = =foodetype.tostring ()) { the -M

This problem may be overlooked, and I have encountered it in the project. Wrote a reminder to everyone!!!When using JavaScript's parseint function, the parseint ("08") or parseint ("09") returned is actually 0, while parseint ("07") is correct, it is difficult to understand at first, It was later discovered that the problem was that when "0" was in front of it, JavaScript's debugger would think of it as an octal number, while "08" and "09" were not a valid octal number, which caused the problem,

In javascript events, when the parameter is an encoded value, javascript will perform the decoding in the following code. In addition, because javascript supports function parameters, the following code can be used: Two features can cause the following security problems: When

Firefox, even objects have the target attribute, but there is no srcelement attribute. Workaround: Use Srcobj = event.srcelement? Event.srcElement:event.target; If the 8th question is considered, replace the event with MyEvent instead. Xi. the question of window.location.href Problem Description: Under IE or firefox2.0.x, you can use Window.location or window.location.href;firefox1.5.x, only use window.location. WORKAROUND: Use window.location instead of window.location.href. Of course, yo

through the database property.Two. About literal assignment, array assignment? 1234567 vara=1,b=2;var c=[a,b];console.log(c);//[1,2]var b=3;console.log(c);//[1,2]varc=[a,b];console.log(c);//[1,3] The value assigned to a, a, B is a number, C is an array of a and a, because the value of a B is 1 and 2, so var c=[a,b] is equal to Var c=[1,2], after which the value of a and B is changed to c=[1,2] irrelevant.The above is a summary of the problem of the dataset in

Here I will briefly discuss the coding problems that often occur in the daily work of front-end HTML and JavaScript. In the computer, the information we store is represented by binary code. What we know, the English and Chinese characters displayed on the screen, and the binary used for storage Code Is the encoding. There are two basic concepts to describe: charset and character encoding: Charset, ch

Simple javascript performance problems and Study Notes I recently read a book titled "high-performance javaScript" and found that many minor details exist in my javaScript writing. Although these problems do not cause program running errors, they may slow the interface load

This article by Bole Online-elviskang translation, into the forest School draft. without permission, no reprint!English Source: adripofjavascript.com. Welcome to join the translation team.The for...in loop of JavaScript is used to iterate over an enumerable (enumerable) property in an object: 1234567891011121314151617 var tMinus = {two: "Two",one: "One",zero: "Blast off!"};var countdown = "";for (var step in tMinus) {countdown += tMin

) { //Get the number of FN parameters var n = fn.length; Declares an array args var args = []; Returns an anonymous function return function (ARG) { //Curryit The arguments in the back brackets to the array Args.push (ARG); If the number of parameters in the args is less than the number of parameters of the FN function, //executes Arguments.callee (which refers to the currently executing function, which is the current anonymous function returned). //Oth