关于javascript:js加减乘除精度丢失问题解决

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/**

解决两个数相加精度失落问题
@param a
@param b
@returns {Number}
*/

export function floatAdd(a, b) {
  var c, d, e;
  if (undefined == a || null == a || "" == a || isNaN(a)) {a = 0;}
  if (undefined == b || null == b || "" == b || isNaN(b)) {b = 0;}
  try {c = a.toString().split(".")[1].length;
  } catch (f) {c = 0;}
  try {d = b.toString().split(".")[1].length;
  } catch (f) {d = 0;}
  e = Math.pow(10, Math.max(c, d));
  return (floatMul(a, e) + floatMul(b, e)) / e;
}

/**

解决两个数相减精度失落问题
@param a
@param b
@returns {Number}
*/

export function floatSub(a, b) {
  var c, d, e;
  if (undefined == a || null == a || "" == a || isNaN(a)) {a = 0;}
  if (undefined == b || null == b || "" == b || isNaN(b)) {b = 0;}
  try {c = a.toString().split(".")[1].length;
  } catch (f) {c = 0;}
  try {d = b.toString().split(".")[1].length;
  } catch (f) {d = 0;}
  e = Math.pow(10, Math.max(c, d));
  return (floatMul(a, e) - floatMul(b, e)) / e;
}

/**

解决两个数相乘精度失落问题
@param a
@param b
@returns {Number}
*/

export function floatMul(a = 0, b = 0) {
  var c = 0,
      d = a.toString(),
      e = b.toString();
  try {c += d.split(".")[1].length;
  } catch (f) { }
  try {c += e.split(".")[1].length;
  } catch (f) { }
  return Number(d.replace(".", "")) * Number(e.replace(".","")) / Math.pow(10, c);
}

/**

解决两个数相除精度失落问题
@param a
@param b
@returns
*/

export function floatDiv(a, b) {
  var c, d, e = 0,
      f = 0;
  try {e = a.toString().split(".")[1].length;
  } catch (g) { }
  try {f = b.toString().split(".")[1].length;
  } catch (g) { }
  return c = Number(a.toString().replace(".", "")), d = Number(b.toString().replace(".","")), floatMul(c / d, Math.pow(10, f - e));
}

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