How to filter data in javascript

Use startWith with getOwnPropertyNames or Object.keys( your_object ).

var apiData = [{
    Value: "895",
    Return: "2",
    Return1: "0.20",
    Return3: "0.40",
    Return5: "0.60",
    Return10: "0.50",
    StartDate: "2019-06-13",
}, {
    Value: "900",
    Return: "4",
    Return1: "0.10",
    Return3: "0.40",
    Return5: "0.70",
    Return10: "0.90",
    StartDate: "2019-06-14",
}]

/* All values of each key thats starts with "Return" in flat array */
const valuesFlat = []
apiData.map( (it, idx) => 
	Object.getOwnPropertyNames(it).filter( prop => prop.startsWith("Return") )
	.map( name => apiData[idx][name]  )
	.forEach( its => valuesFlat.push(its) )
)
console.log( "Flat values" )
console.log( valuesFlat )

/* All values of each key thats starts with "Return", not flat array */
const values = apiData.map( (it, idx) => 
	Object.getOwnPropertyNames(it).filter( prop => prop.startsWith("Return") )
	.map( name => apiData[idx][name]  )
)
console.log("Values")
console.log(values)


const indexes = apiData.map( (it, idx) => 
	Object.getOwnPropertyNames(it)
	.map( (prop, idxs) => { if(prop.startsWith("Return")) return idxs} )
	.filter( prop => prop != undefined )
)
console.log("indexes")
console.log( indexes )



const indexesFlat = []

apiData.forEach( (it, idx) => 
	Object.getOwnPropertyNames(it)
	.map( (prop, idxs) => { if(prop.startsWith("Return")) return idxs} )
	.filter( prop => prop != undefined )
	.forEach( it => indexesFlat.push(it) )
)

console.log("Flat indexes")
console.log( indexesFlat )

const flatPropsWithValues = []
apiData.map( (it, idx) => 
	Object.getOwnPropertyNames(it)
	.filter( prop => prop.startsWith("Return") )
	.forEach( prop => flatPropsWithValues.push( { prop: prop, value: apiData[idx][prop] } ) )
)


console.log("Flat props with values")
console.log( flatPropsWithValues )

Log.d(TAG, "runON " + Thread.currentThread().getName());

Use a regex match and a loop instead:

const ValueData = [];
const re = new Regex('(Return[0-9]{1,2})');
if (ReturnsData) {
  for (const key in ReturnsData) {
    if (if ReturnsData.hasOwnProperty(key) && re.test(key)) {
      ValueData.push(ReturnsData[key]);
    }
  }
}

The regex should match any data starting with 'Return' and ending in one or two numbers. The for...in loop goes through the keys, checks if they exist on the object, and if they match the regex. If they do, the value of that key is added to ValueData.

Assumptions:

I am assuming your keys are always like Return, Return1, Return3, Return5 and Return10 and that your data is already stored in an array (named ReturnsData). In that case you could do the following:

var ValuesData = []; 
if (ReturnsData) {
  ValuesData = ReturnsData.map((item) => {
      return { item.Return, item.Return1, item.Return3, item.Return5, item.Return10 }; 
  });
}

Explanation:

The map function returns by default a new array. That's why we can store the new array directly in ValuesData. Inside the map function, we loop over your objects. Each object's element can then be accessed by item.YOUR_KEY. At the end we are returning a new object. Then the next object is being processed.

First, I think you would be better to use a forEach rather than map since you aren't aren't assigning that statement to a new array and aren't returning anything within the function body. Within the forEach you can iterate through each key and do a regex test to see if the key starts with "Return." If it does, then push the value associated with that key it into your ValuesData array.

let ValuesData = []

ReturnsData.forEach(item => {
    let reg = new RegExp(/^Return.*/)
    for (key in item) {
        if (reg.test(key)) {
            ValuesData.push(item[key]);
        }
    }
})

Which gives you the result:

["2", "0.20", "0.40", "0.60", "0.50", "4", "0.10", "0.40", "0.70", "0.90"]

This will no matter what number comes after Return. So you could have Return12, Return1345, Return76524, etc and still get the desired result.

The following should work :

const ValuesData = [];

if (ReturnsData) {
  ReturnsData.map((item, index) => {
    ValuesData.push({
      ReturnsData[index][`Return${index}`],
    });
  });
}

Returns an array of the values of the keys Return1, Return3, Return5, Return10:

const ReturnsData = {
  Value: "900",
  Return: "4",
  Return1: "0.10",
  Return3: "0.40",
  Return5: "0.70",
  Return10: "0.90",
  StartDate: "2019-06-14"
};

const regex = /Return(1|3|5|10)/;

const ValuesData = Object.entries(ReturnsData)
  .filter(([k, v]) => regex.test(k))
  .map(([k, v]) => v);

console.log(ValuesData);