Detailed explanation of the steps to obtain key and value in js loop map

This time I will bring you a detailed explanation of the steps to obtain key and value with js loop map. What are the precautions for js loop map to obtain key and value? The following is a practical case, let's take a look.

The following method 1 and method 2 have been tested and run by the editor of Script House

Method 1: json format definition

Code 2,

var obj = { 
 "a": 1, 
 "b": 2, 
 "c": 3 
}; 
 
for (var prop in obj) { 
 if (obj.hasOwnProperty(prop)) {  
 // or if (Object.prototype.hasOwnProperty.call(obj,prop)) for safety... 
  alert("prop: " + prop + " value: " + obj[prop]) 
 } 
}

The following are the supplements of other netizens. You can refer to them

javascriptLoopTraverse the arrayOutput key value

javascript loops through the array to output key value
Using the $.each method will definitely not work, so use the following method

markers = [];
    markers[2]=3;
    markers[3]=7;
    for(var key in markers){
      console.log( key )
      console.log( markers[key] )
    }

I believe you have mastered the method after reading the case in this article. For more exciting things, please pay attention to php Other related articles on the Chinese website!

Recommended reading:

How to deal with async/await wasted performance problem

jQuery implementation of fuzzy query practical case analysis

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