Use of array in JavaScript

The array objects in JavaScript are arrays, first a dynamic array, and an ultra-strong complex like C #, "Arrays, lists, hashmap/dictionary" in Java.

Array Arrays

How to use:
Example 1:

var citys = new Array ();//Create an array object without initializing the length, dynamic
Citys[0] = ' Shanghai ';
Citys[1] = ' Beijing ';
CITYS[2] = ' Shenzhen ';

for (var i=0; i< citys.length; i++) {
Alert (Citys[i]);
}

Example 2 ( recommended ):

var arr=[10,true, ' Wow ka ka '];
for (Var i=0;i<arr.length;i++) {
Alert (Arr[i]);
}

Forin traversing array arrays

var arr=[' Hani ', ' Zhuang ', ' Manchu ', ' Drift tribe '];
For (var item in arr) {
Alert (item+ ' = = = ' +arr[item]);
}

array Key-value pairs

How to use

For example:

var arr=new Array ();
arr["name"]= ' Jack ';
arr["Age"]=28;
arr["Gender"]= ' fale ';
arr["Height"]=180;
For (var item in arr) {
Alert (item+ ' = = = ' +arr[item]);
}

Traversing an array key-value pair

Forin Cycle

var arr={name: ' James ', age:28};
For (var item in arr) {
Alert (item+ ' = = = ' +arr[item]);
}

Through the object. Key

var arr={name: ' James ', age:28};
alert (arr.name);
alert (arr.age);

Method Pass Value

function F1 (s) {
alert (s.name);
alert (s.age);
}
F1 ({name: ' Rose ', age:20});

Special guy. Example 1:

var arr=[{name: ' James ', age:19},{name: ' Rose ', age:18},{name: ' Max ', age:20}];
for (Var i=0;i<arr.length;i++) {
Alert (arr[i].name+ ' = = = ' +arr[i].age);
}

Example 2:

var code={name: ' Max ', Children:[{name: ' Jack ', Age:20},{name: ' Rose ', Age:18}]};
alert (code.name);
for (Var i=0;i<code.children.length;i++) {
Alert (code.children[i].name+ ' >> ' +code.children[i].age);
}

Of course Forin can also, but trouble

For (var item in Code.children) {
Alert (item+ ' >> ' +code.children[item].name+ ' = = = ' +code.children[item].age);
}

Array Comparison

Customizing a common comparison method

        function Max (arr,compare) {
            var m=arr[0];
            for (var i=1;i<arr.length;i++) {
                if (compare (arr[i],m) ) {
                     M=arr[i];
               }
           }
            return m;
       }

var S1=max ([12,32,33,100,8],function (N1,N2) {
Return n1>n2;
});
alert (S1);

var s2=max (["AA", "BBBB", "CCC"],function (N1,N2) {
Return n1.length>n2.length;
});

alert (S2);

Comparison method in JavaScript sort ()

Example 1:

var arr=[23,12,56,200,45];
Arr.sort (function (n1,n2) {
Return n1>n2;
});
Alert (arr);

var arrstr=["AA", "BBB", "CCCC"];
Arrstr.sort (function (n1,n2) {
Return n1.length>n2.length;
});
alert (ARRSTR);

Example 2:

var arr=[{name: ' Bob ', age:100},{name: ' Tom ', age:23},{name: ' Rose ', age:78}];
Arr.sort (function (n1,n2) {
Return n1.age>n2.age;
});
for (Var i=0;i<arr.length;i++) {
alert (arr[i].name);//tom,rose,bob
}

Use of array in JavaScript