javascript declare array

global variable destroys the encapsulation performance of the function. function like a black box, usually through the function parameters and return values for input and output, the function of the internal implementation is relatively independent. However, if a global variable is used in a function, the statement in the function body can be accessed by bypassing the function parameter and the return value, which destroys the function's independence and causes the function to rely on the globa

array ' arr.length-= 1;arr.length-= 2 ' * Delete The most subsequent element pop () * Deletes the first element of an array shift () * deletes the specified number of elements at the specified position splice ( index, length) # # # Array traversal* For Loop* For in Span style= "COLOR: #b22222" >### multidimensional

, much less precompiled. functionis a token, indicating that a function is being declared, this keyword is not too much related to a compiler or an interpreter, most of which use this keyword is dynamic type language, and for a static type language such as C/java, Specifying the return value and the parameter list makes it clear that function declarations and function calls are distinguished, because the function itself and the arguments are all typed, but the language of the dynamic type does

[Javascript] (function () {this. title quot; prompt message quot; this. showfunction () {}; this. closefunction () {}; messagethis ;}). (); the role of the above Code is to declare a globally unique object message. Here it declares... [javascript] (Function (){ This. title = "prompt message "; This. show = function (){ }; This. close = function (){ }; Message

sentence in JQuery1.5Window.jquery = window.$ = jQuery;Advantages of Global Variables:You can reduce the number of variables and reduce the time consumption caused by data transfer of actual parameters and formal Parameters.Disadvantages of global Variables:(1) the global variable is stored in a static storage area, which allocates memory for the program to run, and the program ends releasing the Memory. Compared with the dynamic allocation and dynamic release of local variables, the lifetime i

data transfer of actual parameters and formal parameters.Disadvantages of global variables:(1) The global variable is stored in a static storage area, which allocates memory for the program to run, and the program ends releasing the memory. Compared with the dynamic allocation and dynamic release of local variables, the lifetime is relatively long, so too many global variables will occupy more memory units.(2) The global variable destroys the encapsulation performance of the function. function

of the elements in the array.Shift () deletes and returns the first element of the arraySlice () returns the selected element from an existing arraySort () Sorts the elements of an arraySplice () Deletes the element and adds a new element to the array.Tosource () returns the source code of the object.ToString () converts the array to a string and returns the result.toLocaleString () converts the array to a

This article mainly introduces index arrays, associated arrays, static arrays, and dynamic arrays in JavaScript, this article describes how to classify an array into an index array, an associated array, a static array and a dynamic array