Operation of the array

Methods for manipulating arrays (functions):

(common) push () adds a new element from the tail operation is the original array

Pop () deletes an element from the tail

Unshift () Adding elements from the beginning

Shift () removes an element from the beginning

Slice (start, end) gets some elements in the array, returns a new array, and intercepts the end subscript from the start subscript position (without containing the element where the end subscript is located)

Join (string) joins the elements in the array into strings and returns. If join () does not give arguments, separated by commas, or, if given arguments, delimited by the specified delimiter, forming a string return

Splice (start, length) starts from the array start position and deletes length elements. The direct operation is the original array

Common Splice (start, length, element 1, Element 2:) starts from the start position, replacing the corresponding length element as element 1, Element 2 ...

(common) IndexOf () returns the position of the specified element in the array at the first occurrence of 2. Search backward from the specified position, and the corresponding subscript is returned; no return-1 is found

(common) sort () array sort sorted in ascending order of ASCII corresponding values

To sort by numerical numeric size, you need to pass a function that sets the collation as the parameter score is the array to sort

Score.sort (function (x, y) {

return x-y;

});

Console.log (score);

// use Forin when you need to traverse an object

Defining objects

var dog = {

//Key (key) value pair form

Name: "Husky",

age:3,

color: "Gold"

};

For (k in dog) {

console.log (k, dog[k]);

}

Operation of the array