因为在做带小数的计算时，总会出现10.999999998这种类似的结果。
故有了这个插件。
直接上代码：
index.html
<body>
<input type="text" id="number" placeholder="1,2,3">
<br>
<select name="" id="arith">
<option value="0">加法</option>
<option value="1">减法</option>
<option value="2">乘法</option>
<option value="3">除法</option>
</select>
<br>
<button id="btn">计算</button>
<div id="result"></div>
<script>
document.getElementById('btn').onclick = function(){
var number = document.getElementById('number').value;
var meth = document.getElementById('arith').value;
var result = document.getElementById('result');
if(number !== ''){
var arr = number.split(',');
switch (meth){
case "0":
try{
result.innerHTML = arith.sum.apply(arith,arr);
}catch(e){
console.log(e.name+': '+ e.msg);
}
break;
case "1":
try{
result.innerHTML = arith.exc.apply(arith,arr);
}catch(e){
console.log(e.name+': '+ e.msg);
}
break;
case "2":
try{
result.innerHTML = arith.mul.apply(arith,arr);
}catch(e){
console.log(e.name+': '+ e.msg);
}
break;
case "3":
try{
result.innerHTML = arith.div.apply(arith,arr);
}catch(e){
console.log(e.name+': '+ e.msg);
}
break;
default:
throw{
name:'Error',
msg:meth
}
break;
}
}else{
result.innerHTML = '请输入计算数';
}
}
</script>
</body>
arith.js
var arith={
data:[],
/**检查入参的数据类型 */
_int: function(){
var i,flag=true,arr=[],c=0;
for(i=0;i<this.data.length;i++){
var num = this.data[i].toString().replace(/ +/g,'');
num = num.replace(/,/g,'');
if(isNaN(Number(num))){
flag = false;
return false;
}
arr.push(Number(num));
var d;
try{
d = this.data[i].toString().split('.')[1].length;
}catch(e){
d = 0;
}
c = Math.max(c,d);
}
if(flag){
arr.max = c;
return arr;
}else{
return false;
}
},
/**加法 */
sum: function(){
this.data = arguments;
if(this._int()){
var data = this._int();
var i,result=0;
for(i=0;i<data.length;i++){
var d;
try{
d = data[i].toString().split('.')[1].length;
}catch(e){
d = 0;
}
result += Number(data[i].toString().replace('.',''))*Math.pow(10,data.max - d);
}
return result/Math.pow(10,data.max);
}else{
throw{
name:'Error',
msg:'The arguments of function arith.sum is not Number'
}
}
},
/**减法 */
exc: function(){
this.data = arguments;
if(this._int()){
var data = this._int();
var i,result = 'begain';
for(i=0;i<data.length;i++){
var d;
try{
d = data[i].toString().split('.')[1].length;
}catch(e){
d = 0;
}
if(result == 'begain'){
result = Number(data[i].toString().replace('.',''))*Math.pow(10,data.max - d);
}else{
result += -Number(data[i].toString().replace('.',''))*Math.pow(10,data.max - d);
}
}
return result/Math.pow(10,data.max);
}else{
throw{
name:'Error',
msg:'The arguments of function arith.exc is not Number'
}
}
},
/**乘法 */
mul: function(){
this.data = arguments;
if(this._int()){
var data = this._int();
var i,result='begain',s=0;
for(i=0;i<data.length;i++){
var d;
try{
d = data[i].toString().split('.')[1].length;
}catch(e){
d = 0;
}
s += d;
if(result == 'begain'){
result = Number(data[i].toString().replace('.',''));
}else{
result = result*Number(data[i].toString().replace('.',''));
}
}
return result/Math.pow(10,s);
}else{
throw{
name:'Error',
msg:'The arguments of function arith.mul is not Number'
}
}
},
/**除法 */
div: function(){
this.data = arguments;
if(this._int()){
var data = this._int();
var i,result='begain',s=0,m=0;
for(i=0;i<data.length;i++){
var d;
try{
d = data[i].toString().split('.')[1].length;
}catch(e){
d = 0;
}
if(result == 'begain'){
s = d;
result = Number(data[i].toString().replace('.',''));
}else{
m += d;
result = result/Number(data[i].toString().replace('.',''));
}
}
return result*Math.pow(10,m-s);
}else{
throw{
name:'Error',
msg:'The arguments of function arith.div is not Number'
}
}
}
}
欢迎小伙伴们试用和提bug