Looping through multiple arrays - Pushing into multiple arrays

Question

Currently I have three arrays. AppNames which is an application Name. Number of AddOns which is the number of add ons each application is using. (Both of these arrays are used together. E.G "cirr-contentful-demo" has 1 add on).

Look Below:

var prodArrayAppName = [],
  stgArrayAppName = [],
  devArrayAppName = [],
  prodNoAddOns = [],
  stgNoAddOns = [],
  devNoAddOns = [];

var appNames = ["cirr-contentful-demo", "cirr-contentful-handler-backup", "cirr-test-app"];

var numberAddOne = [1, 5, 7]

var production = [{
    "id": "16",
    "heroku_application": "cirr-contentful-demo",
    "stage": "Production"
},
{
    "id": "4",
    "heroku_application": "cirr-contentful-handler-backup",
    "stage": "Staging"
},
{
    "id": "9",
    "heroku_application": "test-backup",
    "stage": "Development"
}];

What I need is to loop through the production array of objects, match the heroku_application name to the name in the appNames array. Once found check the stage type example: Production, Staging, Development.

The push the application name to the correct array. E.G Production applications to prodArrayAppName. Then grab the number of addOns that application has and put it into the correct NoOfAddons. E.G prodArrayAppName.

Meaning the end game should look like:

prodArrayAppName = [cirr-contentful-demo]
prodNoAddOns = [1]

stgArrayAppName = [cirr-contentful-handler-backu]
stgNoAddOns = [5]

devArrayAppName = [test-backup]
devNoAddOns = [7]

This Is the code I have tried so far, but so far getting no luck:

production.forEach(function(a) {
  appNames.forEach(function(b) {
    numberAddOne.forEach(function(c) {
      if (a === b.heroku_application) {
        if (b.stage === "Production") {
          prodArrayAppName.push(b.heroku_application);
          prodNoAddOns.push(c);
        } else if (b.stage === "Staging") {
          stgArrayAppName.push(b.heroku_application);
          stgNoAddOns.push(c);
        } else {
          devArrayAppName.push(b.heroku_application);
          devNoAddOns.push(c);
        }
      }
    });
  });
});

I suppose my questions is "How to loop through multiple arrays and push into other arrays", Sorry for the poorly worded question. I tried to say what I was meaning by showing what the end goal should look like? — user3180997
– user3180997, Commented Jul 28, 2016 at 7:34
someone would say, SO is not a code market, please show what you tried. — Jiang YD
– Jiang YD, Commented Jul 28, 2016 at 7:37
I have tired nesting loops: production.forEach(function(a) { appNames.forEach(function(b) { numberAddOne.forEach(function(c) { if (a === b.heroku_application){ } }); }); }); I'm super stuck and some help would be appreciated. — user3180997
– user3180997, Commented Jul 28, 2016 at 7:38
Please show us your trying code.Put it in the question.If there is a problem we will help — Kiran Muralee
– Kiran Muralee, Commented Jul 28, 2016 at 7:40

Jamiec · Accepted Answer · 2016-07-28 08:10:29Z

1

You dont need explicit loops at all to acomplish this - make use of reduce:

var init = {
    DevelopmentAppName:[],
    DevelopmentNoAddOns:[],
    StagingAppName:[],
    StagingNoAddOns:[],
    ProductionAppName:[],
    ProductionNoAddOns:[],
};

var appNames = ["cirr-contentful-demo", "cirr-contentful-handler-backup", "cirr-test-app"];

var numberAddOne = [1,5,7]

var production = [
                    {
                    "id":"16",
                    "heroku_application":"cirr-contentful-demo",
                    "stage" : "Production"
                    },
                    {
                    "id":"4",
                    "heroku_application":"cirr-contentful-handler-backup",
                    "stage" : "Staging"
                    },
                    {
                    "id":"9",
                    "heroku_application":"test-backup",
                    "stage" : "Development"
                    }];
                    
var result = production.reduce(function(p,c){
     var idx = appNames.indexOf(c.heroku_application);
     p[c.stage + 'AppName'].push(c.heroku_application);
     p[c.stage + 'NoAddOns'].push(numberAddOne[idx] || 0);
     return p;
}, init);

console.log(result);

edited Jul 28, 2016 at 8:10

answered Jul 28, 2016 at 7:53

Jamiec

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4 Comments

Rajesh Dixit Over a year ago

Is Array.reduce not a looping mechanism?

Jamiec Over a year ago

@Rajesh of course it is. (I said explicit loops!)

user3180997 Over a year ago

I'm getting an error message: Uncaught TypeError: Cannot read property 'push' of undefined on line : p[c.stage + 'AppName'].push(c.heroku_application); Whenever i take the p out of the line it runs but doesnt input anything

Jamiec Over a year ago

@user3180997 - so debug it! add console.log(c.stage) on the line above the one failing - what does it output?

Whothehellisthat · Accepted Answer · 2016-07-28 07:51:29Z

You don't really need nested loops.

For each project in production:
- Find the index of the project's heroku_application in appNames. We'll use that to find the number.
- Switching on the project's stage, add the project's name to (stage)ArrayAppName, and the project's cross-referenced number to (stage)NoAddOns.

production.forEach(function(project) {
  var index = appNames.indexOf(project.heroku_application);
  if (index === -1) { return; }

  switch (project.stage) {
    case "Production":
      prodArrayAppName.push(project.heroku_application);
      prodNoAddOns.push(numberAddOne[index]);
      break;
    case "Staging":
      stgArrayAppName.push(project.heroku_application);
      stgNoAddOns.push(numberAddOne[index]);
      break;
    case "Development":
      devArrayAppName.push(project.heroku_application);
      devNoAddOns.push(numberAddOne[index]);
      break;
  }
});

Kiran Muralee · Accepted Answer · 2016-07-28 09:45:51Z

1

The code you have tried has some problems.The condition check you used if (a === b.heroku_application) itself is wrong.Try the code given below

var prodArrayAppName = [], stgArrayAppName = [], devArrayAppName = [], prodNoAddOns = [], 
stgNoAddOns = [], devNoAddOns = [];

var appNames = ["cirr-contentful-demo", "cirr-contentful-handler-backup", "cirr-test-app"];

var numberAddOne = [1,5,7];

var production = [
                {
                "id":"16",
                "heroku_application":"cirr-contentful-demo",
                "stage" : "Production"
                },
                {
                "id":"4",
                "heroku_application":"cirr-contentful-handler-backup",
                "stage" : "Staging"
                },
                {
                "id":"9",
                "heroku_application":"test-backup",
                "stage" : "Development"
                }];

                production.forEach(function(a) {                    
                         for(var i=0;i<appNames.length;i++)
                         {
                             if(a.heroku_application==appNames[i])
                             {
                                    if(a.stage==="Production")
                                    {
                                        prodArrayAppName.push(appNames[i]);
                                        prodNoAddOns.push(numberAddOne[i]);
                                    }
                                    else if(a.stage==="Staging")
                                    {
                                        stgArrayAppName.push(appNames[i]);
                                        stgNoAddOns.push(numberAddOne[i]);
                                    }
                                    else if(a.stage==="Development")
                                    { 
                                        devArrayAppName.push(appNames[i]);
                                        devNoAddOns.push(numberAddOne[i]);
                                    }

                             }
                         }                          


                });

            //checking code 
            prodArrayAppName.forEach(function(a) {
            alert(a);
            });

edited Jul 28, 2016 at 9:45

answered Jul 28, 2016 at 8:12

Kiran Muralee

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3 Comments

user3180997 Over a year ago

this returns an empty array unfortunately :(

Kiran Muralee Over a year ago

No I have tried it .I will edit with the complete code

Kiran Muralee Over a year ago

@user3180997 Answer has been updated with full code.Please try again

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