Example analysis of Array usage in Javascript

This article describes the usage of Array in Javascript. Share it for your reference. The specific analysis is as follows:

The Array object in JavaScript is an array, first of all, a dynamic array, and a super-strong complex such as C# and "arrays, List, HashMap/Dictionary" in Java.

Array array

How to use:

Example 1:

var citys = new Array();
//Create array object without initializing length, dynamiccitys[0] = 'Shanghai'; 
citys[1] ='Beijing'; 
citys[2] = 'Shenzhen';
for(var i=0; i&lt; ; i++){ 
  alert(citys[i]); 
}

Example 2 (recommended):

var arr=[10,true,'Wow Kak']; 
for(var i=0;i&lt;;i++){ 
  alert(arr[i]); 
}

forin traverses Array array

var arr=['Hani','Zhuang','Manchu','Drifting clan']; 
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]); 
}

Iterate over Array key-value pairs

forin loop

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

Pass Object.

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

Method pass value

function f1(s){ 
  alert(); 
  alert(); 
} 
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<;i++){ 
  alert(arr[i].name+'==='+arr[i].age); 
}

Example 2:

var code={name:'Max',children:[{name:'jack',age:20},{name:'rose',age:18}]}; 
alert(); 
for(var i=0;i&lt;;i++){ 
  alert([i].name+'&gt;&gt;'+[i].age); 
}
//Of course forin can be done, but it's a big dealfor(var item in ){ 
  alert(item+'&gt;&gt;'+[item].name+'==='+[item].age); 
}

Array comparison

Customize a general comparison method

function max(arr,compare){ 
  var m=arr[0]; 
  for(var i=1;i<;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 >; 
});
alert(s2);

Comparison method sort() in Javascript

Example 1:

var arr=[23,12,56,200,45]; 
(function(n1,n2){ 
  return n1>n2; 
}); 
alert(arr);
var arrStr=["aa","bbb","cccc"]; 
(function(n1,n2){ 
  return >; 
}); 
alert(arrStr);

Example 2:

var arr=[{name:'Bob',age:100},{name:'Tom',age:23},{name:'Rose',age:78}]; 
(function(n1,n2){ 
  return >; 
}); 
for(var i=0;i<;i++){ 
  alert(arr[i].name);//Tom,Rose,Bob 
}

I hope this article will be helpful to everyone's JavaScript programming.