"use strict"; var __spreadArrays = (this && this.__spreadArrays) || function () { for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length; for (var r = Array(s), k = 0, i = 0; i < il; i++) for (var a = arguments[i], j = 0, jl = a.length; j < jl; j++, k++) r[k] = a[j]; return r; }; Object.defineProperty(exports, "__esModule", { value: true }); exports.enableBoundaryChecking = exports.float2Fixed = exports.digitLength = exports.round = exports.divide = exports.times = exports.minus = exports.plus = exports.strip = void 0; /** * @desc 解决浮动运算问题,避免小数点后产生多位数和计算精度损失。 * 问题示例:2.3 + 2.4 = 4.699999999999999,1.0 - 0.9 = 0.09999999999999998 */ /** * 把错误的数据转正 * strip(0.09999999999999998)=0.1 */ function strip(num, precision) { if (precision === void 0) { precision = 15; } return +parseFloat(Number(num).toPrecision(precision)); } exports.strip = strip; /** * Return digits length of a number * @param {*number} num Input number */ function digitLength(num) { // Get digit length of e var eSplit = num.toString().split(/[eE]/); var len = (eSplit[0].split('.')[1] || '').length - +(eSplit[1] || 0); return len > 0 ? len : 0; } exports.digitLength = digitLength; /** * 把小数转成整数,支持科学计数法。如果是小数则放大成整数 * @param {*number} num 输入数 */ function float2Fixed(num) { if (num.toString().indexOf('e') === -1) { return Number(num.toString().replace('.', '')); } var dLen = digitLength(num); return dLen > 0 ? strip(Number(num) * Math.pow(10, dLen)) : Number(num); } exports.float2Fixed = float2Fixed; /** * 检测数字是否越界,如果越界给出提示 * @param {*number} num 输入数 */ function checkBoundary(num) { if (_boundaryCheckingState) { if (num > Number.MAX_SAFE_INTEGER || num < Number.MIN_SAFE_INTEGER) { console.warn(num + " is beyond boundary when transfer to integer, the results may not be accurate"); } } } /** * 精确乘法 */ function times(num1, num2) { var others = []; for (var _i = 2; _i < arguments.length; _i++) { others[_i - 2] = arguments[_i]; } if (others.length > 0) { return times.apply(void 0, __spreadArrays([times(num1, num2), others[0]], others.slice(1))); } var num1Changed = float2Fixed(num1); var num2Changed = float2Fixed(num2); var baseNum = digitLength(num1) + digitLength(num2); var leftValue = num1Changed * num2Changed; checkBoundary(leftValue); return leftValue / Math.pow(10, baseNum); } exports.times = times; /** * 精确加法 */ function plus(num1, num2) { var others = []; for (var _i = 2; _i < arguments.length; _i++) { others[_i - 2] = arguments[_i]; } if (others.length > 0) { return plus.apply(void 0, __spreadArrays([plus(num1, num2), others[0]], others.slice(1))); } var baseNum = Math.pow(10, Math.max(digitLength(num1), digitLength(num2))); return (times(num1, baseNum) + times(num2, baseNum)) / baseNum; } exports.plus = plus; /** * 精确减法 */ function minus(num1, num2) { var others = []; for (var _i = 2; _i < arguments.length; _i++) { others[_i - 2] = arguments[_i]; } if (others.length > 0) { return minus.apply(void 0, __spreadArrays([minus(num1, num2), others[0]], others.slice(1))); } var baseNum = Math.pow(10, Math.max(digitLength(num1), digitLength(num2))); return (times(num1, baseNum) - times(num2, baseNum)) / baseNum; } exports.minus = minus; /** * 精确除法 */ function divide(num1, num2) { var others = []; for (var _i = 2; _i < arguments.length; _i++) { others[_i - 2] = arguments[_i]; } if (others.length > 0) { return divide.apply(void 0, __spreadArrays([divide(num1, num2), others[0]], others.slice(1))); } var num1Changed = float2Fixed(num1); var num2Changed = float2Fixed(num2); checkBoundary(num1Changed); checkBoundary(num2Changed); // fix: 类似 10 ** -4 为 0.00009999999999999999,strip 修正 return times(num1Changed / num2Changed, strip(Math.pow(10, digitLength(num2) - digitLength(num1)))); } exports.divide = divide; /** * 四舍五入 */ function round(num, ratio) { var base = Math.pow(10, ratio); return divide(Math.round(times(num, base)), base); } exports.round = round; var _boundaryCheckingState = true; /** * 是否进行边界检查,默认开启 * @param flag 标记开关,true 为开启,false 为关闭,默认为 true */ function enableBoundaryChecking(flag) { if (flag === void 0) { flag = true; } _boundaryCheckingState = flag; } exports.enableBoundaryChecking = enableBoundaryChecking; exports.default = { strip: strip, plus: plus, minus: minus, times: times, divide: divide, round: round, digitLength: digitLength, float2Fixed: float2Fixed, enableBoundaryChecking: enableBoundaryChecking, }; //# sourceMappingURL=index.js.map