js处理小数加减乘除法计算精度问题

不念不忘少年蓝@ 2021-09-24 08:28 454阅读 0赞

先根据小数点的位数，把小数扩大适当的倍数，

/**
         * 计算需要乘以的倍数
         */
        var getMaxBaseNum = function(num1, num2) {
            var baseNum, baseNum1, baseNum2;
            try {
                baseNum1 = num1.toString().split(".")[1].length;
            } catch (e) {
                baseNum1 = 0;
            }
            try {
                baseNum2 = num2.toString().split(".")[1].length;
            } catch (e) {
                baseNum2 = 0;
            }
            return baseNum = Math.pow(10, Math.max(baseNum1, baseNum2));
        }

加法

/**
         * 解决js小数加法计算的bug
         */
        var addition = function (num1, num2) {
        	if(exports.isNumEmpty(num1)){
        		num1 = "0";
        	}
        	if(exports.isNumEmpty(num2)){
        		num2 = "0";
        	}
            var baseNum = getMaxBaseNum(num1, num2);
            return (num1 * baseNum + num2 * baseNum) / baseNum;
        };

减法

/**
         * 解决js小数减法计算的bug
         */
        var subtraction = function (num1, num2) {
        	if(exports.isNumEmpty(num1)){
        		num1 = "0";
        	}
        	if(exports.isNumEmpty(num2)){
        		num2 = "0";
        	}
            var baseNum = getMaxBaseNum(num1, num2);
            return (num1 * baseNum - num2 * baseNum) / baseNum;
        };

乘法

/**
    	 *乘法 精确计算
    	 */
    	var multiply = function (params1,params2){
    		if(!params1){
    			params1 = 0;
    		}
    		if(!params2){
    			params2 = 0;
    		}
    	    var m=0;
    	    var s1=params1.toString();
    	    var s2=params2.toString();   
    	    try{ m += s1.split(".")[1].length;}catch(e){};
    	    try{m += s2.split(".")[1].length;}catch(e){};   
    	    return Number(s1.replace(".",""))*Number(s2.replace(".",""))/Math.pow(10,m) ;
    	};

java版实现方法地址：[https://blog.csdn.net/dhj199181/article/details/95942014][https_blog.csdn.net_dhj199181_article_details_95942014]

[https_blog.csdn.net_dhj199181_article_details_95942014]: https://blog.csdn.net/dhj199181/article/details/95942014