{"id":12345,"date":"2026-08-14T19:20:25","date_gmt":"2026-08-14T11:20:25","guid":{"rendered":"https:\/\/www.zhangxinxu.com\/wordpress\/?p=12345"},"modified":"2026-08-14T19:20:25","modified_gmt":"2026-08-14T11:20:25","slug":"js-math-sumprecise","status":"publish","type":"post","link":"https:\/\/www.zhangxinxu.com\/wordpress\/2026\/08\/js-math-sumprecise\/","title":{"rendered":"\u8fd8\u5728reduce\u6c42\u548c\u5417\uff1f\u8be5\u4f7f\u7528Math.sumPrecise()\u65b9\u6cd5\u5566"},"content":{"rendered":"

by zhangxinxu<\/a> from https:\/\/www.zhangxinxu.com\/wordpress\/?p=12345<\/a>
\n\u672c\u6587\u53ef\u5168\u6587\u8f6c\u8f7d\uff0c\u4f46\u9700\u8981\u4fdd\u7559\u539f\u4f5c\u8005\u3001\u51fa\u5904\u4ee5\u53ca\u6587\u4e2d\u94fe\u63a5\uff0cAI\u6293\u53d6\u4fdd\u7559\u539f\u6587\u5730\u5740\uff0c\u4efb\u4f55\u7f51\u7ad9\u5747\u53ef\u6458\u8981\u805a\u5408\uff0c\u5546\u7528\u8bf7\u8054\u7cfb\u6388\u6743\u3002<\/p>\n

\u4e00\u3001\u6570\u7ec4\u6c42\u548c\u65b0\u65b9\u6cd5<\/h3>\n

\u4e4b\u524d\u5927\u5bb6\u6570\u7ec4\u6c42\u548c\uff0c\u80af\u5b9a\u591a\u534a\u90fd\u662f\u4f7f\u7528\u7684\u6570\u7ec4\u7684reduce<\/code>\u65b9\u6cd5.<\/p>\n

\u4f8b\u5982\uff1a<\/p>\n

const sum = [1, 2, 3, 4, 5, 6].reduce((a, b) => a + b, 0);\r\n\/\/ \u7ed3\u679c sum: 21<\/pre>\n
\u5982\u4e0b\u622a\u56fe\u6240\u793a\uff1a<\/p>\n
\"reduce\u6c42\u548c\u793a\u610f\"<\/p>\n
\u5728\u5927\u591a\u6570\u65f6\u5019\uff0c\u4e0a\u9762\u7684\u6c42\u548c\u8ba1\u7b97\u662f\u6ca1\u95ee\u9898\u7684\u3002<\/p>\n
\u4f46\u662f\uff0c\u5982\u679c\u8ba1\u7b97\u7684\u6570\u503c\u8d85\u5927\uff0c\u8d85\u8fc7\u4e86JS\u7684\u6574\u6570\u8303\u56f4\uff1b\u6216\u8005\u662f\u5c0f\u6570\uff0c\u5c31\u53ef\u80fd\u51fa\u95ee\u9898\u3002<\/p>\n
\u6bd4\u65b9\u8bf4\uff1a<\/p>\n
const arr = [0.1, 0.2, 0.3];\r\n\/\/ reduce\u6c42\u548c\r\nconst sum = arr.reduce((prev, curr) => prev + curr, 0);\r\n\r\nconsole.log(sum);   \r\n\/\/ \u9884\u671f\uff1a0.6\r\n\/\/ \u5b9e\u9645\u8f93\u51fa\uff1a0.6000000000000001<\/pre>\n
const values = [1e20, 0.1, -1e20];\r\n\r\nconst sum = values.reduce((a, b) => a + b, 0);\r\nconsole.log(\"sum\", sum);\r\n\/\/ \u9884\u671f\uff1asum 0.1\r\n\/\/ \u5b9e\u9645\uff1asum 0<\/pre>\n
\u8fd9\u600e\u4e48\u5f04\uff1f<\/p>\n
\u5728\u8fc7\u53bb\uff0c\u5f00\u53d1\u4eba\u5458\u4f1a\u628a\u6570\u7ec4\u6bcf\u4e00\u9879\u90fd\u4e58\u4ee5100,1000\u8fd9\u79cd\uff0c\u7136\u540e\u518d\u8ba1\u7b97\uff0c\u4f8b\u5982\uff1a<\/p>\n
const sum = [0.1, 0.2, 0.3].reduce((prev, curr) => prev + curr * 100, 0) \/ 100;\r\nconsole.log(sum);   \r\n\/\/ \u9884\u671f\uff1a0.6\r\n\/\/ \u5b9e\u9645\u8f93\u51fa\uff1a0.6\r\n<\/pre>\n
\u6216\u8005\u4f7f\u7528Number.toPrecision()<\/code>\u65b9\u6cd5\u5bf9\u8f93\u51fa\u503c\u8fdb\u884c\u7cbe\u5ea6\u683c\u5f0f\u5316\u5904\u7406\u3002<\/p>\n
\u4f8b\u5982\uff1a<\/p>\n
const moneyList = [0.1, 0.2, 0.7, 0.3];\r\nconst total = moneyList.reduce((s, v) => s + v, 0);\r\n\r\nconsole.log(total); \r\n\/\/ \u9884\u671f\uff1a1.3\r\n\/\/ \u5b9e\u9645\uff1a1.2999999999999998\r\n\r\nconsole.log(Number(total.toPrecision(16))); \r\n\/\/ \u9884\u671f\uff1a1.3\r\n\/\/ \u5b9e\u9645\uff1a1.3\r\n<\/pre>\n
\u7136\u800c\uff0c\u4e0a\u9762\u8fd9\u4e9b\u65b9\u6cd5\u90fd\u4e0d\u662f\u5b8c\u5168\u4e4b\u7b56\uff0c\u4f8b\u5982 toPrecision()<\/code> \u65b9\u6cd5\u5728\u4e0b\u9762\u8fd9\u4e2a\u6848\u4f8b\u4e2d\u5c31\u662f\u65e0\u6548\u7684\uff1a<\/p>\n
[1e20, 0.1, -1e20].reduce((s, v) => s + v, 0).toPrecision(16)\r\n\/\/ \u7ed3\u679c\u8fd8\u662f0.000000000000000 \u274c<\/pre>\n
\u90a3\u600e\u4e48\u529e\u5462\uff1f<\/p>\n
\u6709\u6ca1\u6709\u4ec0\u4e48\u4e00\u4e86\u767e\u4e86\u7684\u65b9\u6cd5\u5462\uff1f<\/p>\n
\u6709\uff01<\/p>\n
\u90a3\u5c31\u662fMath<\/code>\u5bf9\u8c61\u65b0\u589e\u7684sumPrecise()<\/code>\u65b9\u6cd5\u3002<\/p>\n
\u4e00\u952e\u6c42\u548c\uff0c\u540c\u65f6\u4fdd\u8bc1\u7cbe\u5ea6\u3002<\/p>\n
\u4e8c\u3001\u6570\u7ec4\u6c42\u548c\u5229\u5668Math.sumPrecise()<\/h3>\n
\u4ece\u4eca\u5f80\u540e\uff0c\u6570\u7ec4\u6c42\u548c\uff0c\u518d\u4e5f\u65e0\u9700\u4f7f\u7528reduce()<\/code>\u65b9\u6cd5\u4e86\uff0c\u76f4\u63a5Math.sumPrecise()<\/code>\u65b9\u6cd5\u4e00\u628a\u68ad\u3002<\/p>\n
\u4f7f\u7528\u975e\u5e38\u7b80\u5355\uff0c\u4f8b\u5982\uff1a<\/p>\n
const sum = Math.sumPrecise([1, 2, 3, 4, 5, 6]);\r\n\/\/ \u7ed3\u679c sum: 21<\/pre>\n
\u540c\u65f6\uff0c\u518d\u4e5f\u6ca1\u6709\u5c0f\u6570\u8ba1\u7b97\u7cbe\u5ea6\u4e0d\u51c6\u7684\u95ee\u9898\u4e86\u3002<\/p>\n
const sum = Math.sumPrecise([0.1, 0.2, 0.3]);\r\n\/\/ \u7ed3\u679c sum: 0.3<\/pre>\n
\u8d85\u5927\u7684\u6574\u6570\u8ba1\u7b97\u4e5f\u4e0d\u4f1a\u6709\u95ee\u9898\u4e86\uff01<\/p>\n
\r\nconst values = [1e20, 0.1, -1e20];\r\nconst sum = Math.sumPrecise(values);\r\nconsole.log(\"sum\", sum);\r\n\/\/ sumTwo 0.1<\/pre>\n
\"\u592a\u68d2\u5566\uff0c\u8868\u60c5\u5305\"<\/p>\n
\u4e09\u3001\u517c\u5bb9\u6027\u3001Polyfill\u4e0e\u7ed3\u8bed<\/h3>\n
\u5404\u5927\u6d4f\u89c8\u5668\u5bf9Math.sumPrecise()<\/code>\u65b9\u6cd5\u7684\u652f\u6301\u975e\u5e38\u79ef\u6781\uff0c\u76ee\u524d\u9886\u5148\u7684\u51e0\u4e2a\u7248\u672c\u90fd\u5df2\u7ecf\u652f\u6301\u3002<\/p>\n
\"Math<\/p>\n
\u5bf9\u4e8e\u4e0d\u517c\u5bb9\u7684\u6d4f\u89c8\u5668\uff0c\u53ef\u4ee5\u5f15\u5165Polyfill\u4ee3\u7801\uff0c\u53c2\u8003\u793a\u610f\uff1a<\/p>\n
if (typeof Math.sumPrecise !== 'function') {\r\n  Object.defineProperty(Math, 'sumPrecise', {\r\n    value: function sumPrecise(items) {\r\n      \/\/ \u53c2\u6570\u6821\u9a8c\r\n      if (items == null) {\r\n        throw new TypeError('Math.sumPrecise requires an iterable argument.');\r\n      }\r\n      if (typeof items[Symbol.iterator] !== 'function') {\r\n        throw new TypeError('Math.sumPrecise: argument is not iterable.');\r\n      }\r\n\r\n      var sum = 0;\r\n      var compensation = 0; \/\/ Neumaier \u8865\u507f\u503c\r\n      var count = 0;\r\n      var hasNegZero = false;\r\n      var hasNonZero = false;\r\n\r\n      for (var value of items) {\r\n        var num = Number(value);\r\n\r\n        \/\/ \u4efb\u610f\u5143\u7d20\u4e3a NaN\uff0c\u76f4\u63a5\u8fd4\u56de NaN\r\n        if (Number.isNaN(num)) {\r\n          return NaN;\r\n        }\r\n\r\n        \/\/ \u4efb\u610f\u5143\u7d20\u4e3a \u00b1Infinity\uff0c\u5904\u7406\u65e0\u7a77\u5927\u76f8\u6d88\u95ee\u9898\r\n        if (!isFinite(num)) {\r\n          if (sum === Infinity && num === -Infinity) return NaN;\r\n          if (sum === -Infinity && num === Infinity) return NaN;\r\n          sum = num;\r\n          hasNonZero = true;\r\n          count++;\r\n          continue;\r\n        }\r\n\r\n        \/\/ \u8bb0\u5f55 -0\r\n        if (num === 0) {\r\n          if (!isFinite(sum) || hasNonZero) {\r\n            \/\/ \u6709\u5b9e\u9645\u6570\u503c\u65f6 -0 \u4e0d\u5f71\u54cd\u7ed3\u679c\r\n          } else if (Object.is(num, -0)) {\r\n            hasNegZero = true;\r\n          }\r\n          count++;\r\n          continue;\r\n        }\r\n\r\n        hasNonZero = true;\r\n\r\n        \/\/ Neumaier \u8865\u507f\u6c42\u548c\u6838\u5fc3\r\n        var t = sum + num;\r\n        if (Math.abs(sum) >= Math.abs(num)) {\r\n          compensation += (sum - t) + num;\r\n        } else {\r\n          compensation += (num - t) + sum;\r\n        }\r\n        sum = t;\r\n\r\n        count++;\r\n        if (count > 2 ** 53) {\r\n          throw new RangeError('Math.sumPrecise: iterable is too large.');\r\n        }\r\n      }\r\n\r\n      \/\/ \u5168\u662f\u96f6\uff08\u542b -0\uff09\u7684\u60c5\u51b5\r\n      if (!hasNonZero) {\r\n        return hasNegZero ? -0 : 0;\r\n      }\r\n\r\n      \/\/ \u6709\u65e0\u7a77\u5927\u65f6\uff0c\u8865\u507f\u503c\u65e0\u610f\u4e49\uff0c\u76f4\u63a5\u8fd4\u56de\r\n      if (!isFinite(sum)) {\r\n        return sum;\r\n      }\r\n\r\n      return sum + compensation;\r\n    },\r\n    writable: true,\r\n    configurable: true,\r\n  });\r\n}<\/pre>\n
\u8fb9\u754c\u6d4b\u8bd5\u7528\u4f8b\uff1a<\/p>\n
\/\/ \u7cbe\u5ea6\u95ee\u9898\r\nMath.sumPrecise([0.1, 0.2, 0.3])          \/\/ 0.6\r\nMath.sumPrecise([0.1, 0.1, 0.1, 0.1,\r\n                 0.1, 0.1, 0.1, 0.1,\r\n                 0.1, 0.1])                \/\/ 1\r\n\r\n\/\/ \u7279\u6b8a\u503c\r\nMath.sumPrecise([])                        \/\/ 0\r\nMath.sumPrecise([-0])                      \/\/ -0\r\nMath.sumPrecise([-0, -0])                  \/\/ -0\r\nMath.sumPrecise([-0, 0])                   \/\/ 0\uff08\u6b63\u96f6\u4f18\u5148\uff09\r\nMath.sumPrecise([Infinity, -Infinity])     \/\/ NaN\r\nMath.sumPrecise([NaN, 1])                  \/\/ NaN\r\nMath.sumPrecise([Infinity, 1, 2])          \/\/ Infinity\r\n\r\n\/\/ \u975e\u6570\u7ec4\u53ef\u8fed\u4ee3\r\nMath.sumPrecise(new Set([1, 2, 3]))        \/\/ 6\r\nMath.sumPrecise((function*() {\r\n  yield 0.1; yield 0.2; yield 0.3;\r\n})())                                      \/\/ 0.6\r\n<\/pre>\n
\u770b\u8d77\u6765\u8fd8\u633a\u50cf\u90a3\u4e48\u56de\u4e8b\u3002<\/p>\n
\u597d\u4e86\uff0c\u5c31\u8bf4\u8fd9\u4e48\u591a\u5427\u3002<\/p>\n
\u5927\u5bb6\u5468\u672b\u6109\u5feb\u3002<\/p>\n
\"\u5468\u672b\u6109\u5feb\"<\/p>\n
\u672c\u6587\u4e3a\u539f\u521b\u6587\u7ae0\uff0c\u4f1a\u7ecf\u5e38\u66f4\u65b0\u77e5\u8bc6\u70b9\u4ee5\u53ca\u4fee\u6b63\u4e00\u4e9b\u9519\u8bef\uff0c\u56e0\u6b64\u8f6c\u8f7d\u8bf7\u4fdd\u7559\u539f\u51fa\u5904\uff0c\u65b9\u4fbf\u6eaf\u6e90\uff0c\u907f\u514d\u9648\u65e7\u9519\u8bef\u77e5\u8bc6\u7684\u8bef\u5bfc\uff0c\u540c\u65f6\u6709\u66f4\u597d\u7684\u9605\u8bfb\u4f53\u9a8c\u3002
\n\u672c\u6587\u5730\u5740\uff1ahttps:\/\/www.zhangxinxu.com\/wordpress\/?p=12345<\/a><\/p>\n
\uff08\u672c\u7bc7\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"
\"Math.sumPrecise\u65b9\u6cd5\u5c01\u9762\u56fe\"<\/p>\n
\u6570\u7ec4\u6c42\u548c\u8fd8\u5728\u4f7f\u7528reduce()\u65b9\u6cd5\u5417\uff1fOut\u5566\uff01\u65e2\u9ebb\u70e6\uff0c\u53c8\u6709\u8ba1\u7b97\u7cbe\u5ea6\u7684\u95ee\u9898\uff0c\u4ece\u4eca\u5929\u5f00\u59cb\uff0c\u6539\u7528Math.sumPrecise()\u65b9\u6cd5\u5427\uff01<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[1887,1474,106,1237,798,2148,2152,669],"_links":{"self":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/12345"}],"collection":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/comments?post=12345"}],"version-history":[{"count":7,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/12345\/revisions"}],"predecessor-version":[{"id":12366,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/12345\/revisions\/12366"}],"wp:attachment":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=12345"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=12345"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=12345"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}