update

src/money/numberToWords2.ts

+const digits = ['零', '壹', '贰', '叁', '肆', '伍', '陆', '柒', '捌', '玖'] as const
+const units = ['', '拾', '佰', '仟'] as const
+const units2 = ['', '万', '亿'] as const
+const units3 = ['角', '分', '厘'] as const
+
+export default function numberToWords(input: string | number): string {
+  const number = Number(input)
+  if (number >= 10 ** 13) throw new Error('数字太大')
+  if (number < 0) throw new Error('数字不能为负数')
+  if (number === 0) return '零元整'
+  let [integer = '', decimal = ''] = String(number).split('.')
+  integer = integer.padStart(12, '0').slice(-12)
+  decimal = decimal.padEnd(2, '0').slice(0, 2)
+  let result = ''
+  if (integer) {
+    let preNull = true
+    let zero = false
+    let blank = true
+    for (let i = 0; i < integer.length; i++) {
+      const j = integer.length - i - 1
+      const bit1 = units[j % 4]
+      const bit2 = units2[Math.floor(j / 4)]
+      const digit = digits[Number(integer[i])]
+      if (digit === '零') {
+        if (preNull) continue
+        zero = true
+      }
+      if (j % 4 === 3) blank = true
+      if (digit !== '零') {
+        preNull = false
+        blank = false
+        if (zero) {
+          zero = false
+          result += '零'
+        }
+        result += digit + bit1
+      }
+      if (j % 4 === 0 && !blank) result += bit2
+    }
+  }
+  if (result) result += '元'
+  if (!decimal || decimal === '00') return result + '整'
+  if (decimal) {
+    for (let i = 0; i < decimal.length; i++) {
+      const digit = digits[Number(decimal[i])]
+      if (result && i === 0 && digit === '零') {
+        result += '零'
+      }
+      if (digit !== '零') {
+        result += digit + units3[i]
+      }
+    }
+  }
+  return result
+}

test/money/numberToWords.test.ts

@@ -2,6 +2,9 @@ import { describe, it, expect } from 'vitest'
 import numberToWords from '../../src/money/numberToWords'
 
 describe('测试整数', () => {
+  it('0 toBe 零元整', () => {
+    expect(numberToWords(0)).toBe('零元整')
+  })
   it('1 toBe 壹元整', () => {
     expect(numberToWords(1)).toBe('壹元整')
   })