js的浮点运算很不准确,但是可以进行正确的整型运算,所以可以将浮点数变大倍数成整型,运算出结果后再变小原来的倍数。比如0.2+0.3=[(0.2*10)+(0.3*10)]/10=0.5
这里我封装了加减乘除四个方法,在js中进行数值运算时可以直接调用。
module.exports = { add: function(arg1, arg2) { var r1, r2, m; try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 } try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 } m = Math.pow(10, Math.max(r1, r2)) return (arg1 * m + arg2 * m) / m }, sub: function(arg1, arg2) { var r1, r2, m; try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 } try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 } m = Math.pow(10, Math.max(r1, r2)) return (arg1 * m - arg2 * m) / m }, mul: function(arg1, arg2) { var m = 0, s1 = arg1.toString(), s2 = arg2.toString(); try { m += s1.split(".")[1].length } catch (e) {} try { m += s2.split(".")[1].length } catch (e) {} return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m) }, div: function(arg1, arg2) { var t1 = 0, t2 = 0, r1, r2; try { t1 = arg1.toString().split(".")[1].length } catch (e) {} try { t2 = arg2.toString().split(".")[1].length } catch (e) {} r1 = Number(arg1.toString().replace(".", "")) r2 = Number(arg2.toString().replace(".", "")) return (r1 / r2) * Math.pow(10, t2 - t1); } }