87 行
3.5 KiB
JavaScript
可执行文件
87 行
3.5 KiB
JavaScript
可执行文件
// console.log('1.43', toDecimal(0.95 * 1.5));
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// console.log('2.87', toDecimal(3.82 * 0.75));
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// console.log('2', toDecimal(9.5 * 0.21));
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// console.log('2', toDecimal(9.5 * 0.021));
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// console.log('8.08', toDecimal(9.5 * 0.85));
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// console.log('2.76', toDecimal(0.95 * 2.9));
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// console.log('1.45', toDecimal(1.444999999999));
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// console.log('1.44', toDecimal(1.444699999999));
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// console.log('1.2', toDecimal(1.2));
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// console.log('1.0', toDecimal(1.0));
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// console.log('1.11', toDecimal(1.11));
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// console.log('1.10', toDecimal(1.10));
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// console.log('1.111', toDecimal(1.111));
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// console.log('1.110', toDecimal(1.110));
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// console.log('5.5', toDecimal(5.5, 0));
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// console.log('5.6', toDecimal(5.6, 0));
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// console.log('5.4999999', toDecimal(5.4999999, 0));
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// console.log('5', toDecimal(5, 0));
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// console.log('0.01', toDecimal(0.01, 2));
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// console.log('0', toDecimal(0.000001, 0));
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// console.log('0', toDecimal(0.000001, 2));
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// console.log('0', toDecimal(0, 2));
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/**
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* 保留任意位小数
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* @param number 数值
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* @param precision 保留小数位数
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* @param toFixed 是否四舍五入
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* @param isNumber 返回值是否为数值类型
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* @returns {any}
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*/
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function toDecimal(number, precision = 2, toFixed = true, isNumber = true) {
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(number == undefined || number == null || number == "" || Number.isNaN(number)) && (number = 0)
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let newNumber = String(number);
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let arr = newNumber.split(".");
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arr[0] == '' && (arr[0] = 0);
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// 如果不是小数，补充对应的0
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if (arr.length === 1) {
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return isNumber ? Number(newNumber) : (newNumber + "." + "0".repeat(precision))
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} else {
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// 如果是小数 但位数比要保留的位数少 也是要补0
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if (arr[1].length <= precision) {
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return isNumber ? Number(newNumber) : (newNumber + "0".repeat(precision - arr[1].length));
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} else {
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let intNumber = parseInt(arr[0]);// 整数部分
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let decimal = String(arr[1]);// 所有小数部分
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let frontDecimal;//有效小数部分
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if (Number(decimal) == 0) {
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frontDecimal = 0
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} else {
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if (decimal.length <= precision) {
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//小数量小于所需小数位
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frontDecimal = decimal;
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} else {
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//小数量大于所需小数位
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frontDecimal = (precision > 0 ? (decimal.substr(0, precision)) : 0) * 1;
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let moreDecimal = parseInt(decimal.substr(precision, 1));
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let spliceNumber = decimal.substr(precision, 5);
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if (spliceNumber === '49999') {
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moreDecimal += 1;
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}
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if (moreDecimal >= 5) {
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frontDecimal += 1;
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}
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//判断小数部位是否需要进位 类似于19.996 保留2位小数 就是20.00
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if (frontDecimal === Math.pow(10, precision)) {
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frontDecimal = '0'.repeat(precision)
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intNumber += 1;
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}
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//处理 0.015 0.009 保留的小数中有0出现的情况
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if (String(frontDecimal).length < precision) {
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frontDecimal = '0'.repeat(precision - String(frontDecimal).length) + frontDecimal
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}
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}
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}
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return isNumber ? Number(`${intNumber}.${frontDecimal}`) : `${intNumber}.${frontDecimal}`
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}
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}
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}
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