具有JavaScript循环参考问题

Question

我有一个函数createminor4（arr，tourney）它基本上将arr分成4组，每组8个，然后一次将它们交换为tourney 1组。从那里，它推入四个{}，其中有四个带有空数组的键。

我已经在Chrome中浏览了整个步骤，在第一组推送之后，其余各组会相互覆盖，即使我要在四组中使用不同的键{}。我以循环引用结尾，不明白我在做什么错。

let players4 = [
  "Lava Lamps", "Jarheads", "Cloud Gazerz", "Cobras", "Red Ravens", "Leaders", "Destroyers", "shooters",
  "Yellow Dragons", "Whales", "fearwolves", "Hitters", "red rebels", "Knights", "cute gremlins", "water pistols",
  "Snakes", "Ravens", "Chariots-of-Hell", "Predators", "Assassins", "Gladiators", "Broncos", "Hawks",
  "Gamers", "Slickers", "Freeze", "Rabbits", "Holy Rollers", "Crusaders", "FireHawks", "Worms"
]
let minorTourny = [
  ["t1", "t2"],
  ["t3", "t4"],
  ["t5", "t6"],
  ["t7", "t8"],
  ["a", "b"],
  ["c", "d"],
  ["e", "f"],
  ["g"]
];

function createMinor4(arr, tourney) {
  let q = arr.length * .25;
  let s = 0;
  let p = 1;
  let g = 4;
  let x = 0;
  let y = 0;
  let z = 0;

  let four = {
    "A": [],
    "B": [],
    "C": [],
    "D": []
  }
  //while 4 > 0
  while (g > s) {
    do {
      let loadTeam = tourney[x].splice(y, 1, arr[z]);
      if (z === 0) {
        loadTeam;
        y++;
      } else if (z % 2 == 0) {
        loadTeam;
        y = 1;
      } else if (z % 2 !== 0) {
        loadTeam;
        y = 0;
        x++;
      }
      z++;
    }
    while (z < q) // while 0 < 8
    if (g === 4) {
      four.A.push(tourney);
    } else if (g === 3) {
      four.B.push(tourney);
    } else if (g === 2) {
      four.C.push(tourney);
    } else if (g === 1) {
      four.D.push(tourney);
    }
    arr.splice(0, q)
    g--;
    p++;
    z = 0;
    x = 0;
    y = 0;
  }
  return four
}
console.log(createMinor4(players4, minorTourny))

Answer 1

当您在数组上使用splice时，也会更改原始数组，这就是为什么players4函数调用后minorTourny和createMinor4不相同的原因您可以使用Deep copy当您使用深层复制时，它将不再具有原始数组的引用。

let players4 = [
  "Lava Lamps", "Jarheads", "Cloud Gazerz", "Cobras", "Red Ravens", "Leaders", "Destroyers", "shooters",
  "Yellow Dragons", "Whales", "fearwolves", "Hitters", "red rebels", "Knights", "cute gremlins", "water pistols",
  "Snakes", "Ravens", "Chariots-of-Hell", "Predators", "Assassins", "Gladiators", "Broncos", "Hawks",
  "Gamers", "Slickers", "Freeze", "Rabbits", "Holy Rollers", "Crusaders", "FireHawks", "Worms"
]
let minorTourny = [
  ["t1", "t2"],
  ["t3", "t4"],
  ["t5", "t6"],
  ["t7", "t8"],
  ["a", "b"],
  ["c", "d"],
  ["e", "f"],
  ["g"]
];

function createMinor4(_arr, _tourney) {
  const arr = JSON.parse(JSON.stringify(_arr)); // Use Deep copy
  const tourney = JSON.parse(JSON.stringify(_tourney)); // Use Deep copy
  let q = arr.length * .25;
  let s = 0;
  let p = 1;
  let g = 4;
  let x = 0;
  let y = 0;
  let z = 0;

  let four = {
    "A": [],
    "B": [],
    "C": [],
    "D": []
  }
  //while 4 > 0
  while (g > s) {
    do {
      let loadTeam = tourney[x].splice(y, 1, arr[z]);
      if (z === 0) {
        loadTeam;
        y++;
      } else if (z % 2 == 0) {
        loadTeam;
        y = 1;
      } else if (z % 2 !== 0) {
        loadTeam;
        y = 0;
        x++;
      }
      z++;
    }
    while (z < q) // while 0 < 8
    if (g === 4) {
      four.A.push(tourney);
    } else if (g === 3) {
      four.B.push(tourney);
    } else if (g === 2) {
      four.C.push(tourney);
    } else if (g === 1) {
      four.D.push(tourney);
    }
    arr.splice(0, q)
    g--;
    p++;
    z = 0;
    x = 0;
    y = 0;
  }
  return four
}
console.log(createMinor4(players4, minorTourny))