Pushing items from first array of objects to another array of objects

Question

defaultParameterTypes = [] // this is my empty array



const propsArray = this.props.device.deviceProperties.defaultParameterTypes;      
 const defaultParameterTypes = this.state.deviceSettings.defaultParameterTypes;

when i checked on checkbox i want to push into my defaultParameterTypes array the object but the case is when the type is repeated dont push it twice.

"propsArray": "[{'name': '1','type': '11'}, {'name': '2','type': '22'}, {'name': '3','type': '11'}, {'name': '4','type': '11'}, {'name': '5','type': '22'}, {'name': '6','type': '22'}, {'name': '7','type': '22'}]",

i want to make like loop and check if it is not found in defaultEmptyArray and push it if not found but i dont need the type to be repeated in mydefaultarray

So have you made the loop to check to push elements or not? Update your question with your attempt and where you are getting stuck. — Drew Reese
– Drew Reese, Commented Jan 31, 2020 at 9:07
for (let i = 0; i < propsArray.length; i++) { if (e.target.checked) { if (propsArray[i].type === defaultParameterTypes[j].type) { alert("Dont Push this type") // break; } else { alert("Push this type"); defaultParameterTypes.push(propsArray[i]); // break; } }} — Abbass
– Abbass, Commented Jan 31, 2020 at 9:10
i was trying like this but i need to make like to check if it is found in defaultParameterTypes or not — Abbass
– Abbass, Commented Jan 31, 2020 at 9:11
What is your expected result? If type seen again, don't copy, or only maintain one copy overall, i.e. overwrite it each time so the last one seen is what remains? — Drew Reese
– Drew Reese, Commented Jan 31, 2020 at 9:12

Drew Reese · Accepted Answer · 2020-01-31 09:47:19Z

1

Simple way would be to create a map of the types seen in the array and reduce your input array into it, then get the array of values from the map you created.

const data = [
  { name: "1", type: "11" },
  { name: "2", type: "22" },
  { name: "3", type: "11" },
  { name: "4", type: "11" },
  { name: "5", type: "22" },
  { name: "6", type: "22" },
  { name: "7", type: "22" }
];

// reduce array into map of type => { name, type }
// then get the object values array
const reducedData = Object.values(
  data.reduce((acc, { name, type}) => {
    if (!acc[type]) acc[type] = { name, type }; // if not seen type, store
    return acc;
  }, {})
);

console.log(reducedData)

Expand on this concept to create a function that takes two arrays and processes the second into the first.

const data = [
  { name: "1", type: "11" },
  { name: "2", type: "22" },
  { name: "3", type: "44" },
  { name: "4", type: "11" },
  { name: "5", type: "22" },
  { name: "6", type: "33" },
  { name: "7", type: "22" }
];

const data2 = [
  { name: "1", type: "33" },
  { name: "2", type: "22" },
  { name: "3", type: "66" },
  { name: "4", type: "11" },
  { name: "5", type: "22" },
  { name: "6", type: "44" },
  { name: "7", type: "22" }
];

const data3 = [
  { name: "1", type: "66" },
  { name: "2", type: "22" },
  { name: "3", type: "33" },
  { name: "4", type: "11" },
  { name: "5", type: "55" },
  { name: "6", type: "11" },
  { name: "7", type: "44" }
];

const reduceData = (currentArray = [], newArray = []) => {
  const mapFn = (acc, { name, type }) => {
    if (!acc[type]) acc[type] = { name, type }; // if not seen type, store
    return acc;
  };
  const createMap = array => array.reduce(mapFn, {});

  return Object.values(newArray.reduce(mapFn, createMap(currentArray)));
};

const reducedData = reduceData(data, data2);
const reducedData1 = reduceData(reducedData, data3);

console.log(reducedData);
console.log(reducedData1);

edited Jan 31, 2020 at 9:47

answered Jan 31, 2020 at 9:22

Drew Reese

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12 Comments

Abbass Over a year ago

but i need one more thing in same issue

Abbass Over a year ago

i want to compare the 2 arrays the default and the props array

Abbass Over a year ago

( i want to compare only the type of the object) that if first item in propsArray is not fount in defaultParameterTypes array then push the object to defaultParameterTypes

Abbass Over a year ago

Thanks alot Mr. Drew

Abbass Over a year ago

But the first is better

|

pope_maverick · Accepted Answer · 2020-01-31 11:09:39Z

0

let hasValue = (arr, obj) => arr && arr.filter(item => item.type == obj.type).length

let result = propsArray.reduce((acc, curr) => {
 if (hasValue(acc, curr)) {
  return acc;
 } else {
  return [...acc, curr]
 }
}, []);

will give u an array with all the elements where the type property is unique..

hope this is what ur expected result..

let result = propsArray.reduce((acc, curr) => {
 if (hasValue(acc, curr)) {
  return [...acc, { name: curr.name }];
 } else {
  return [...acc, curr]
 }
}, []);

or if type reccurs, copy only the name object..

this will return an array of same length but along the elements, type property will be removed if it recurrs...

edited Jan 31, 2020 at 11:09

answered Jan 31, 2020 at 10:52

pope_maverick

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8 Comments

Abbass Over a year ago

if you please send me your email to contact you and send you the screenshot and what i am facing

Abbass Over a year ago

and really thank you very much you helped me to think more when you send your examples

Abbass Over a year ago

if (checked) { defaultParameterTypes.push({ "name": e.target.name, "type": e.target.value }) this.setState({ deviceSettings: { ...this.state.deviceSettings, defaultParameterTypes } }); }

Abbass Over a year ago

else { let defaultParameterTypes = this.state.deviceSettings.defaultParameterTypes; const i = defaultParameterTypes.findIndex( item => item.type === e.target.value ); defaultParameterTypes = defaultParameterTypes.slice(0, i).concat( defaultParameterTypes.slice(i + 1, defaultParameterTypes.length) );

Abbass Over a year ago

this.setState({ deviceSettings: { ...this.state.deviceSettings, defaultParameterTypes } }) }

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