Get höchsten und niedrigsten in jedem Element aus mehreren Arrays in JavaScript

Question

Ich habe dieses Array mit 4 Reihen von Elementen 18 (** zur Folge bezieht, die nicht Teil der Code-/Array):

highlow: [["-5", "8", "-8", "13", "17", "11", "17", "4", "17", "18", "18", "10", "-8", "-13", "-22", "-16", "-3", "27"], 
["5", "**15**", "6", "-11", "-18", "-7", "-6", "7", "-10", "5", "6", "-6", "-12", "-10", "-7", "14", "10", "23"], 
["-6", "7", "8", "18", "6", "14", "24", "14", "6", "13", "8", "18", "-14", "-15", "-9", "-13", "14", "12"], 
["-19", "-12", "14", "20", "15", "20", "11", "19", "13", "5", "2", "-14", "5", "6", "16", "-5", "8", "30"]] 

Ich brauche Holen Sie sich zwei neue Arrays mit dem höchsten der 18 Elemente und einem mit dem niedrigsten. Ich habe dies gemacht:

var highlow = []; 
var high = []; 
var low = []; 

for (i = 0; i < 18; i++) { 
     high.push("0"); 
     low.push("0"); 
}     

for (var l = 0; l < highlow.length; l++) { 

        for (var m = 0; m < highlow[0].length; m++) { 
         // High 
          if (highlow[l][m] > high[m]) { 
           high.splice(m, 1, highlow[l][m]); 
          }  
         // Low 
          if (highlow[l][m] < low[m]) { 
           low.splice(m, 1, highlow[l][m]); 
          } 
        } 
        } 

Aber das Ergebnis ich dieses erhalten ist, auf dem zweiten Hoch Element es 8 zurück, aber das sollte 15 (siehe **) sein:

high: 
["5","**8**","8","20","6","20","24","7","6","5","8","18","5","6","16","14","8","30"] 
low: 
["-19","-12","14","-11","15","-7","11","19","13","5","2","-14","-14","-15","-9","-5","-3","12"] 

Ich kippe herauszufinden, wie dies zu bewerkstelligen ...

Underscore.js ist markiert, wenn das eine Verknüpfung sein könnte ...

Answer 1

Sie diese Ergebnisse bekommen, weil Sie Strings sind zu vergleichen, keine Zahlen.

console.log("15" > "8"); // false 
 
console.log(15 > 8); // true

zu Zahlen konvertieren, wenn der Vergleich die richtigen Ergebnisse liefern zu tun:

var input = [ 
 
    ["-5", "8", "-8", "13", "17", "11", "17", "4", "17", "18", "18", "10", "-8", "-13", "-22", "-16", "-3", "27"], 
 
    ["5", "15", "6", "-11", "-18", "-7", "-6", "7", "-10", "5", "6", "-6", "-12", "-10", "-7", "14", "10", "23"], 
 
    ["-6", "7", "8", "18", "6", "14", "24", "14", "6", "13", "8", "18", "-14", "-15", "-9", "-13", "14", "12"], 
 
    ["-19", "-12", "14", "20", "15", "20", "11", "19", "13", "5", "2", "-14", "5", "6", "16", "-5", "8", "30"] 
 
]; 
 

 
var high = []; 
 
var low = []; 
 
for (var i=0; i<input[0].length; i++) { 
 
    for (var j = 0; j<input.length; j++) { 
 
     if (!high[i] || Number(input[j][i]) > Number(high[i])) { high[i] = input[j][i];} 
 
     if (!low[i] || Number(input[j][i]) < Number(low[i])) { low[i] = input[j][i];} 
 
    } 
 
} 
 

 
console.log("high:", high); 
 
console.log("low:", low);

(tauschte ich die Reihenfolge, in der die Arrays ausgewertet werden, so dass Sie wouldn‘ t muss die Ausgabe vorinitialisieren, aber ansonsten ist dies ähnlich wie bei Ihrem Code mit Ausnahme der Number() Konvertierungen.)

Answer 2

Sie können alle Werte in ein einzelnes Array ablegen, die Werte sortieren und das Array dann halbieren, um Arrays mit hohem und niedrigem Wert zu erstellen.

let superArray = []; 
superArray.push(highlow[0]); 
superArray.push(highlow[1]); 
superArray.push(highlow[2]); 
superArray.push(highlow[3]); 

superArray.sort(); 

let lowArray = superArray.splice(0, superArray.length -1); 
let highArray = superArray; 

Answer 3

Sie könnten die Min- und Max-Werte reduzieren.

function highlow(array) { 
 
    return array.reduce(function (r, a, i) { 
 
     if (!i) { 
 
      r.low = a.slice(); 
 
      r.high = a.slice(); 
 
      return r; 
 
     } 
 
     a.forEach(function (b, j) { 
 
      r.low[j] = Math.min(r.low[j], b); 
 
      r.high[j] = Math.max(r.high[j], b); 
 
     }) 
 
     return r; 
 
    }, { low: [], high: [] }); 
 
} 
 

 
console.log(highlow([["-5", "8", "-8", "13", "17", "11", "17", "4", "17", "18", "18", "10", "-8", "-13", "-22", "-16", "-3", "27"], ["5", "15", "6", "-11", "-18", "-7", "-6", "7", "-10", "5", "6", "-6", "-12", "-10", "-7", "14", "10", "23"], ["-6", "7", "8", "18", "6", "14", "24", "14", "6", "13", "8", "18", "-14", "-15", "-9", "-13", "14", "12"], ["-19", "-12", "14", "20", "15", "20", "11", "19", "13", "5", "2", "-14", "5", "6", "16", "-5", "8", "30"]]));

Answer 4

Verwenden Math.min() und Math.max():

var high = [], low = []; 
for (i = 0; i < highlow[0].length; i++) { 
    var col = highlow.map(val => val[i]); 
    high.push(col.reduce((a,b)=>Math.max(a,b))); 
    low.push(col.reduce((a,b)=>Math.min(a,b))); 
} 

Answer 5

Hoffe, dass es helfen:

var highlow =[["-5", "8", "-8", "13", "17", "11", "17", "4", "17", 
    "18", "18", "10", "-8", "-13", "-22", "-16", "-3", "27"], 
    ["5", "15", "6", "-11", "-18", "-7", "-6", "7", "-10", "5", "6", 
    "-6", 
    "-12", "-10", "-7", "14", "10", "23"], 
    ["-6", "7", "8", "18", "6", "14", "24", "14", "6", "13", "8", 
    "18", 
    "-14", "-15", "-9", "-13", "14", "12"], 
    ["-19", "-12", "14", "20", "15", "20", "11", "19", "13", "5", "2", 
    "-14", "5", "6", "16", "-5", "8", "30"]] 

var high=[]; 
var low=[]; 
highlow.map((a)=>{ 
    hight.push(Math.max(...a)); 
    low.push(Math.min(...a)); 
});