Add sum of all numbers in an array and print the final result-CodePudding

please don't kill me right away, because some topics are already here in the forum. I've read and tried a lot. I just don't get any further with my beginner knowledge.

My problem is the following: I have 4 arrays, the length of the arrays can have a different length each time. Now I would like to add the sum of all 4 arrays and get a final result.

I just can't really get any further than I want. Please bear with me and help me.

Here my example :

var MyData = '{"M":[{"M":{"MD":995,"PT":1,"TT":17,"D":0,"TID":44,"T":0,"HW":109,"KD":0,"TA":[4,17,77,17010,84,5,6,6,6,5,"xxxx",0,0,128,6,-1,0,34,[],0],"SD":1187,"OD":117,"SA":[1,65,67,194,187,7,8,7,6,6,"yyyy",0,0,-1,-1,-1,0,95,[],0]},"UM":{"PD":0,"TD":0,"L":{"ID":23,"ID":2,"VIS":14,"N":"bbbb","GD":102,"L":17,"W":1429,"D":113,"SPR":9,"Q":[[1647,1,2,5,-1,[[4,40,[114.0]],[5,46,[74.3]],[18,89,[43.6]],[116,34,[42.2]]],-1,-1,0,-1,-1,3,[1,5,3090,[7222,32,5,310,[[312,46,[11.4]],[311,55,[12.8]],[34,72,[19.7]],[30,28,[8.4]]],0]]],[187,2,2,5,-1,[[1,9,[82.4]],[2,86,[86.3]],[112,67,[28.1]],[19,35,[22.0]]],-1,-1,0,-1,-1,3,[2,6,2970,[7127,32,6,3240,[[311,28,[8.5]],[314,67,[18.7]],[32,83,[17.3]],[315,46,[8.0]]],0]]],[14650745,3,2,5,-1,[[3,97,[116.8]],[6,55,[74.8]],[109,42,[24.8]],[116,65,[67.0]]],-1,-1,0,-1,-1,3,[3,6,3590,[77381,32,6,3130,[[313,33,[6.3]],[310,83,[21.1]],[312,61,[13.8]],[311,36,[9.8]]],0]]],[14673,4,2,5,-1,[[7,82,[16.1]],[115,40,[21.0]],[121,87,[215,871.0]],[112,48,[22.4]]],-1,-1,0,-1,-1,3,[4,6,3570,[72077,32,2,2710,[[312,44,[11.0]],[311,52,[12.3]],[313,37,[6.8]],[38,38,[8.8]]],0]]],[14681483230,5,2,0,0,[[21,[5.0]]],1070,-1,0,630006,-1,2],[14649672824,6,2,15,-1,[[808,82,[47.1]],[811,77,[28.1]],[812,50,[20.0]],[815,35,[18.4]],[20018,100,[1.0]],[20016,7,[2060,12.0,2061,12.0,2062,12.0,2063,12.0,2064,12.0,2065,12.0,2066,12.0,2067,12.0,2068,12.0,148,12.0,2069,12.0,149,12.0,2070,12.0,150,12.0,151,12.0,2071,12.0,2072,12.0,2073,12.0,2074,12.0,2075,12.0,2076,12.0,2077,12.0,2078,12.0,2079,12.0,2020,12.0,2021,12.0,2022,12.0,2023,12.0,2024,12.0,2025,12.0,2026,12.0,2027,12.0,2028,12.0,2029,12.0,2030,12.0,2031,12.0,2032,12.0,2033,12.0,2034,12.0,2035,12.0,2036,12.0,2037,12.0,2038,12.0,2039,12.0]]],-1,-1,0,-1,-1,3,[65,6,3440,[]]]],"IDS":[[10021,1023],[10022,1033]],"SIS":[1033,1009,1040,100253],"AE":[[64,[8.0]],[503,[20.0]],[504,[48.0]],[504,[48.0]],[339,[50.0]],[504,[48.0]],[613,[50.0]],[66,[65.0]],[503,[65.0]],[503,[45.0]],[504,[30.0]],[504,[45.0]],[614,[8.0]],[66,[48.0]],[504,[60.0]],[66,[45.0]],[504,[48.0]],[614,[30.0]],[66,[24.0]]]}},"GA":{"L":[[287,30],[216,2224],[215,744],[298,60],[651,76],[650,90],[649,132],[240,50]],"M":[[287,30],[216,2720],[215,3808],[298,60],[651,48],[650,102],[649,125],[648,179],[240,50]],"R":[[287,30],[216,2968],[298,60],[651,76],[650,90],[649,132],[240,50]],"RW":[[215,2358],[216,433]]},"AST":[390,400],"ATT":0,"SM":0}],"O":[{"OID":8344,"DUM":false,"N":"xrr","E":{"BGT":0,"BGC1":14408394,"BGC2":1644825,"SPT":2,"S1":82,"SC1":144394,"S2":82,"SC2":163,"IS":1},"L":7,"LL":50,"H":3195,"AVZ":180,"CF":3911,"HF":16245,"PRE":13,"SUF":23,"TPX":-1,"MP":459,"R":0,"AID":48,"AR":0,"AN":"drum vv","aee":{"CF":237604,"BGT":7,"BGC1":16825,"BGC2":3012,"BGC3":864,"SPT":23,"S1":2,"SC1":30512,"S2":41,"SC2":164825,"S3":0,"SC3":164825},"RPT":0,"AP":[[0,1007,1062,76,1],[0,1170610,1067,757,4],[0,1211752,1056,755,4],[0,100,1059,72,4],[1,163,710,79,12],[2,16771,809,68,12],[3,2052697,772,504,12]],"VP":[],"SA":0,"VF":0,"PF":1,"RRD":0,"TI":-1},{"OD":1187,"DM":false,"N":"xyz","E":{"BGT":1,"BG1":81264,"BG2":5126,"SPT":1,"S1":82,"S1":16425,"S2":82,"S2":164825,"IS":1},"L":7,"LL":90,"H":6738,"AVP":87345,"CF":4591,"HF":5623,"PRE":13,"SUF":27,"TX":1,"P":8828,"R":0,"AD":88,"AR":7,"AN":"DDR ","aee":{"CF":1878,"BT":2,"BC1":14494,"BG2":1894,"BC3":-1,"SPT":0,"S1":-1,"S1":-1,"S2":-1,"SC2":-1,"S3":-1,"SC3":-1},"RPT":0,"AP":[[0,1417194,675,607,1],[0,2086,795,1180,4],[0,3363161,663,603,4],[0,7164676,769,1179,4],[1,489,490,318,12],[2,208,33,71,12],[3,4347,42,108,12],[4,112,818,61,12]],"VP":[],"A":0,"VF":0,"PF":1,"RD":0,"TI":-1,"RP":-1}]}'

var MyArray = JSON.parse(MyData)

MyArray.M[0].GA.L.forEach(element1 => console.log(element1[1]));
MyArray.M[0].GA.M.forEach(element2 => console.log(element2[1]));
MyArray.M[0].GA.R.forEach(element3 => console.log(element3[1]));
MyArray.M[0].GA.RW.forEach(element4 => console.log(element4[1]));

//So I give myself all the values first.

//If I then use the for loop on one of the arrays, I get the output:

let sum = 0;

MyArray.M[0].GA.L.forEach(element1 => {
  

const MyArray = [element1[1]];

 for (let i = 0; i < MyArray.length; i  ) {
    sum  = MyArray[i];
}
console.log(sum); 
  
})

//output: 30,2254,2998,3058,3134,3224,3356,3406

The number 3406 is the End Result, how can I print only the End result.

If there is another method to add all 4 arrays together at once, it would help me even more.

If possible an example for an array and an example for all 4 together please

CodePudding user response：

you have to do three things: consolidate all the arrays, get the sum of all values, then print it

first, consolidate

const allArrs = [
  ...MyArray.M[0].GA.L,
  ...MyArray.M[0].GA.M,
  ...MyArray.M[0].GA.R,
  ...MyArray.M[0].GA.RW
]

then, the array method that would help the most here is Array.Reduce

const result = allArrs.reduce((accumulator, currentArray) => {
  accumulator  = currentArray[1]
  return accumulator
}, 0)

then log the result!

CodePudding user response：

As others have pointed out, this type of problem is very well suited for using a functional programming approach, where you simplify the problem by morphing it into a series of atomic operations that have no side-effects.

JavaScript does a great job of implementing the core functional programming methods of map(), filter(), and reduce(). For this problem, the only thing you need is reduce().

The code below could be made smaller and more efficient, but it was written to show each individual step.

const data = JSON.parse(rawData);

// subData is now an object whose members are the arrays you care about
const subData = data.M[0].GA;

// turn that into an array of arrays
const myArrays = Object.values(subData);

// now use reduce() to flatten the array of arrays into a single array with just
// the numbers you want to sum
const myNums = myArrays.reduce((acc, val) => acc.concat(val[1]), []);

// finally, reduce() again to sum the values
const sum = myNums.reduce((acc, val) => acc   val, 0);

console.log(sum);

CodePudding user response：

You're on the right track. Simply move console.log(sum) outside of the final }) so it's not inside any loops.

CodePudding user response：

I hope I understand what you are trying to do. You can simplify your code in this way.

function sum(arr) {
 return arr.reduce((acc, item) => acc  = item[1], 0);
}

const result = sum(MyArray.M[0].GA.L)   sum(MyArray.M[0].GA.M)   sum(MyArray.M[0].GA.R)   sum(MyArray.M[0].GA.RW);

CodePudding user response：

This is a good example of a use for Array.prototype.reduce. The reduce method loops through all the elements of an array, and uses an accumulator to carry a result through the operation.

const someArray = [ /* any number of values */ ]
const sum = someArray.reduce( ( acc, val ) => ( acc   val )

You can take this a step further and write the callback as a function expression, and dump all of your arrays into a BIGGER array, and use reduce on THAT ONE too!

const summation = ( acc, val ) => ( acc   val )
const sumOfSums = ( acc, val ) => ( acc   val.reduce( summation, 0 ) )

const arrayOfArrays= [
  MyArray.M[0].GA.L,
  MyArray.M[0].GA.M,
  MyArray.M[0].GA.R
  MyArray.M[0].GA.RW
]

const total = arrayOfArrays.reduce( sumOfSums, 0 )
console.log( `output: ${total}` )