如何干掉这些 JS 数学计算

Question

我下面有这些重复的数学计算，我想弄清楚如何让它们变干。

const d     = store.state.logbook.summary,
      AIR   = ([d.AIR/d.TOT]*100).toFixed(2),
      PIC   = ([d.PIC/d.TOT]*100).toFixed(2),
      PMC   = ([d.PMC/d.TOT]*100).toFixed(2),
      VO    = ([d.VO/d.TOT]*100).toFixed(2),
      TRNG  = ([d.TRNG/d.TOT]*100).toFixed(2);

this.chartData = [
  100, +AIR, +PIC, +PMC, +VO, +TRNG
]
console.log(this.chartData)
// Returns: [100, 97.44, 84.65, 84.65, 2.56, 12.79]!

Answer 1

您可以获取一个键数组，映射计算值，取消移位 100 并分配给想要的目标。

const
    d = store.state.logbook.summary,
    data = ['AIR', 'PIC', 'PMC', 'VO', 'TRNG'].map(k => +(d[k] * 100 / d.TOT).toFixed(2));

data.unshift(100);
this.chartData = data;
console.log(this.chartData);

将每个部分拆分成更小的单元只是问题的另一种观点，例如

获取对象的值
通过获取函数的绑定第一个参数并映射值来获取百分比值
将值格式化为最多两位数。

const
    getPercent = (whole, part) => part * 100 / whole,
    getNumFixed2 = value => +value.toFixed(2),
    d = { AIR: 28, PIC: 9, PMC: 2, VO: 56, TRNG: 25, TOT: 120 }, // store.state.logbook.summary,
    data = ['AIR', 'PIC', 'PMC', 'VO', 'TRNG']
        .map(k => d[k])
        .map(getPercent.bind(null, d.TOT))
        .map(getNumFixed2);

data.unshift(100);
console.log(data);

如何干掉这些 JS 数学计算

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