用于根据用户 input/max 值交换变量的 JS 函数

Question

我正在尝试做一个简单的成本估算器。有 3 个不同输入的最大值。我想制作一个检查输入值的函数，并尝试确保 z 值始终是三个值中的最低值，只要满足全局约束。

我做了这个代码笔：

http://codepen.io/FredHair/pen/Jdberw?editors=001

这是我的变量交换代码：

function retrVals() {
  var coOrds = {}; //empty object
  coOrds.x = Number(document.getElementById("x").value); //define each coordinate
  coOrds.y = Number(document.getElementById("y").value);
  coOrds.z = Number(document.getElementById("z").value);
  var min = Math.min(coOrds.x,coOrds.y,coOrds.z); //find the minimum of the three
  var temp = coOrds.z; //create a temporary variable to store the current z value
  var limitx = 241;
  var limity = 191;
  var limitz = 331;
  if(min === coOrds.z && coOrds.z < limitz && coOrds.x < limitx && coOrds.y < limity){
    return [coOrds.x,coOrds.y,coOrds.z]
  }
  else if(min === coOrds.y && coOrds.z < limity && coOrds.x < limitx && coOrds.y < limitz){
    coOrds.z = coOrds.y
    coOrds.y = temp
    return [coOrds.x,coOrds.y,coOrds.z]
  }
  else if(min === coOrds.x && coOrds.z < limitx && coOrds.x < limitz && coOrds.y < limity){
    coOrds.z = coOrds.y
    coOrds.y = temp
    return [coOrds.x,coOrds.y,coOrds.z]
  }
  else{
    return [coOrds.x,coOrds.y,coOrds.z]
  }
};

约束是：

  x = 240;
  y = 190;
  z = 330;

所以我不想交换会破坏该数量的值，而且我也总是希望尽可能使 z 最低。[=14=]

执行此操作的最佳方法是什么？我的代码是在正确的轨道上还是有更好的方法？

如有任何帮助，我们将不胜感激。

弗雷德

Answer 1

如果我对你的理解正确的话，这个 if 语句应该做你想做的事情：

var temp = coOrds.z; //create a temporary variable to store the current z value
var limitx = 241, limity = 191, limitz = 331;
var xFail, yFail, zFail;

coOrds.x >= limitx ? xFail = true : xFail = false;
coOrds.y >= limity ? yFail = true : yFail = false;
coOrds.z >= limitz ? zFail = true : zFail = false;

if (zFail || (xFail && yFail)) { // z failed OR both x AND y failed, we cant ever handle this because if x failed then x is greater than 240 which wont ever fit into y

  // dont accept the input, z-fail can't be handled because if it doesnt fit in z it wont fit in x or y either

} else if (yFail) { // only y failed

  if (coOrds.y < limitx && coOrds.x < limity) { // can we swap x and y?
    var tmp = coOrds.y;
    coOrds.y = coOrds.x;
    coOrds.x = tmp;
  } else if (coOrds.y < limitz && coOrds.z < limity) { // can we swap z and y?
    var tmp = coOrds.y;
    coOrds.y = coOrds.z;
    coOrds.z = tmp;

  }

} else if (xFail) { // only x failed

  if (coOrds.x < limity && coOrds.y < limitx) { // can we swap x and y ?
    var tmp = coOrds.y;
    coOrds.y = coOrds.x;
    coOrds.x = tmp;
  } else if (coOrds.y < limitz && coOrds.z < limity) { // can we swap z and x?
    var tmp = coOrds.x;
    coOrds.x = coOrds.z;
    coOrds.z = tmp;

  }
}

if (min < coOrds.z) { //do we need to swap at all?
  coOrds.z = min; // set z to the minimum
  if (min == coOrds.x && temp < limitx) { // was x the minimum and was z less than the x limit?
    coOrds.x = temp; //x is the new z
  } else if (temp < limity) { // y was the minimum, was z less than the y limit?
    coOrds.y = temp;
  } else { // could not swap, would exceed limits
    coOrds.z = temp
  }
}


return [coOrds.x,coOrds.y,coOrds.z];

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