增加加减乘除去除精度问题方法

v2.0/src/utils/common/math.ts

+/** @format */
+//加法
+export function add(num1: number, num2: number): number {
+  const num1Decimal = num1.toString().split('.')[1] || ''
+  const num2Decimal = num2.toString().split('.')[1] || ''
+  const num1DecimalLength = num1Decimal.length
+  const num2DecimalLength = num2Decimal.length
+  //计算小数位数位数差值
+  if (num1DecimalLength >= num2DecimalLength) {
+    //如果前一位比后一位大，则后一位补位计算精度
+    return (
+      (num1 * Math.pow(10, num1DecimalLength + 1) +
+        num2 * Math.pow(10, num2DecimalLength + 1) * Math.pow(10, num1DecimalLength - num2DecimalLength)) /
+      Math.pow(10, num1DecimalLength + 1)
+    )
+  } else {
+    return (
+      (num2 * Math.pow(10, num2DecimalLength + 1) +
+        num1 * Math.pow(10, num1DecimalLength + 1) * Math.pow(10, num2DecimalLength - num1DecimalLength)) /
+      Math.pow(10, num2DecimalLength + 1)
+    )
+  }
+}
+//减法
+export function subtract(num1: number, num2: number): number {
+  const num1Decimal = num1.toString().split('.')[1] || ''
+  const num2Decimal = num2.toString().split('.')[1] || ''
+  const num1DecimalLength = num1Decimal.length
+  const num2DecimalLength = num2Decimal.length
+  //计算小数位数位数差值
+  if (num1DecimalLength >= num2DecimalLength) {
+    //如果前一位比后一位大，则后一位补位计算精度
+    return (
+      (num1 * Math.pow(10, num1DecimalLength + 1) -
+        num2 * Math.pow(10, num2DecimalLength + 1) * Math.pow(10, num1DecimalLength - num2DecimalLength)) /
+      Math.pow(10, num1DecimalLength + 1)
+    )
+  } else {
+    return (
+      (num1 * Math.pow(10, num1DecimalLength + 1) * Math.pow(10, num2DecimalLength - num1DecimalLength) -
+        num2 * Math.pow(10, num2DecimalLength + 1)) /
+      Math.pow(10, num2DecimalLength + 1)
+    )
+  }
+}
+//乘法
+export function multiply(num1: number, num2: number): number {
+  const num1Decimal = num1.toString().split('.')[1] || ''
+  const num2Decimal = num2.toString().split('.')[1] || ''
+  const num1DecimalLength = num1Decimal.length
+  const num2DecimalLength = num2Decimal.length
+  //计算小数位数位数差值
+  return (
+    (num1 * Math.pow(10, num1DecimalLength + 1) * (num2 * Math.pow(10, num2DecimalLength + 1))) /
+    Math.pow(10, num1DecimalLength + num2DecimalLength + 2)
+  )
+}
+
+//除法
+export function divide(num1: number, num2: number): number {
+  const num1Decimal = num1.toString().split('.')[1] || ''
+  const num2Decimal = num2.toString().split('.')[1] || ''
+  const num1DecimalLength = num1Decimal.length
+  const num2DecimalLength = num2Decimal.length
+  //计算小数位数位数差值
+  if (num1DecimalLength >= num2DecimalLength) {
+    //如果前一位比后一位大，则后一位补位计算精度
+    return (
+      (num1 * Math.pow(10, num1DecimalLength + 1)) /
+      (num2 * Math.pow(10, num2DecimalLength + 1) * Math.pow(10, num1DecimalLength - num2DecimalLength))
+    )
+  } else {
+    return (
+      (num1 * Math.pow(10, num1DecimalLength + 1) * Math.pow(10, num2DecimalLength - num1DecimalLength)) /
+      (num2 * Math.pow(10, num2DecimalLength + 1))
+    )
+  }
+}

v2.0/src/utils/index.ts

@@ -27,3 +27,5 @@ export * from './common/userUpdate'
 export * from './common/format'
 
 export * from './common/doHandler'
+
+export * from './common/math'