Array type of JS

• Variable-length array object
-0-based
-Maximum length: 2 ^ 32 −1 = 4294967295
• Construct an array object
-New array (): empty array
-New array (3): An array with a length of 3
-New array (1, "hello"): constructs an array with two elements

Array. prototype. ...
• Length attribute: array length, read/write
• Tostring ()/tolocalestring () method:
-Returns a comma-separated string.
-The difference between the two is the way to get each object string
• Concat ([Item1 [, item2 [,... ]) Method:
-Return a new array to save all elements and parameters of the original array.
• Push ([Item1 [, item2 [,... ]) Method:
-Add one or more elements at the end of the array.
• Pop method:
-Remove and return elements from the end of the array
• Shift method:
-Remove and return elements from the array Header
• Unshift ([Item1 [, item2 [,... ]) Method:
-Add one or more elements to the array header.
• Join (separator) method:
-Returns a string that uses separator as the delimiter to connect all elements.
-The basis of stringbuilder can accelerate String concatenation for IE
• Reverse () method: reverse all elements in the array
• Sort (comparefunction) method:
-The parameter is a method used to compare two elements.
-If the parameter is omitted, use <, =,> to compare two elements.
• Slice (START, end) method:
-The new array is returned, which does not affect the old array.
-Contains elements starting from subscript start to subscript end-1
-If end is omitted, all elements starting from the subscript start to the end are included.
-If the parameter is negative, it indicates the subscripts (I .e., the subscript is n + array. Length) of the array's "reciprocal)
-If the start element is after the end element or is the same, an empty array is returned.
-If the parameter is negative, it indicates the subscripts (I .e., the subscript is n + array. Length) of the array's "reciprocal)
-If the start element is after the end element or is the same, an empty array is returned.
• Splice (START, deletecount [, Item1 [, item2 [,... ]) Method:
-The most flexible method affects the current array
-Delete the deletecount element from the element of the subscript start and insert the remaining element at the current start position.
-Delete element: splice (2, 1)
-Insert element: splice (2, 0, "hello", "world ")
-Replacement element: splice (2, 1, "hello", "world ")

Html < Div ID = " Info " > </ Div >
< Script Language = " Javascript " Type = " Text/JavaScript " >
Function display (text)
{
Document. getelementbyid ( " Info " ). Innerhtml + = (Text +   " <Br/> " );
}

Array. Prototype. Display = Function ()
{
Window. Display ( " A: "   +   This );
}

VaR =   New Array ( 1 , 2 , 3 , 4 , 5 ); // A = [1, 2, 3, 4, 5];
Display ( " Array initialized " );
A. Display ();

Display ( " A. Push (6, 7) " );
A. Push ( 6 , 7 );
A. Display (); // [1, 2, 3, 4, 5, 6, 7]

Display ( " A. Shift (): "   + A. Shift ());
A. Display (); // [2, 3, 4, 5, 6, 7]

Display ( " A. unshift (8) " );
A. unshift ( 8 );
A. Display (); // [8, 2, 3, 4, 5, 6, 7];

Display ( " A. Pop (); "   + A. Pop ());
A. Display (); // [8, 2, 3, 4, 5, 6];

Display ( " A. Concat (9, 10 ): "   + A. Concat ( 9 , 10 )); // [8, 2, 3, 4, 5, 6, 9, 10];
A. Display (); // [8, 2, 3, 4, 5, 6]

Display ( " '[' + A. Join ('] [') + ']': "   +   ' [ '   + A. Join ( ' ] [ ' ) +   ' ] ' ); // [8] [2] [3] [4] [5] [6];

Display ( " A. Slice (2, 5 ): "   + A. Slice ( 2 , 5 )); // [3, 4, 5]
Display ( " A. Slice (2,-2 ): "   + A. Slice ( 2 , - 2 )); // [3, 4]
A. Display ();

Display ( " A. splice (3, 2) " );
A. splice ( 3 , 2 );
A. Display (); // [8, 2, 3, 6]

Display ( " A. splice (2, 0, 7, 8) " );
A. splice ( 2 , 0 , 7 , 8 );
A. Display (); // [8, 2, 7, 8, 3, 6]

Display ( " A. splice (3, 1, 9, 10) " );
A. splice ( 3 , 1 , 9 , 10 );
A. Display (); // [8, 2, 7, 9, 10, 3, 6]

Display ( " A. Reverse () " );
A. Reverse ();
A. Display (); // [6, 3, 10, 9, 7, 2, 8]

Display ( " A. Sort () " );
A. Sort ();
A. Display (); // [10, 2, 3, 6, 7, 8, 9]

Display ( " A. Sort (function (x, y) {return y-X ;}); " );
A. Sort (function (x, y ){ Return Y - X ;});
A. Display (); // [10, 9, 8, 7, 6, 3, 2];
</ Script >