有没有办法按顺序在javascript中执行数组操作？ [英] Is there any way to do array operations by order in javascript?

问题描述

我的代码中有一个输入框。从输入字符串我得到运算符和操作数。 
 
如果用户输入10 * 20/30  -  60 + 2，我得到的值是getElementById 
 
所以现在的问题是，有没有办法做这个数组按顺序运作？ 
 
我期待这样的计算如下：
 
 10 * 20是200 
 200/30是6.66 
 6.66  -  60是-53.33 
 -53.33 + 2是-51.33 
所以-51.33必须是最终答案。 
 
我已经通过eval（）函数尝试了这个计算，但我得到的答案是错误的。我也想在同一输入框中显示该答案，请不要给我两个文本框的示例。 
 
我已经尽可能地描述了我的问题。您可以在评论框中看到我的代码链接。 
 
另一种解释方式，例如[10 * 2 - >答案 - > 回答/ 30 - >回答 - > 答案 -  60 - >回答 - > 回答+ 2 - >回答] 

我尝试了什么：

我的代码链接： -  jsfiddle.net/archan/z3mqnxz7

解决方案

< blockquote>

< pre>  function  getResult（exp）{
 exp = '  1 *' + exp; 
  var  parts = exp.split（'  ）; 
  var  result，num = []，exp = [];  var  formu = []; 
 
  for （ var  i =  0 ; i< parts.length; i ++）{
  var  item = parts [i] .trim（）; 
  if （ isNaN （item））
 exp.push（item）; 
  else  
 num.push（item）; 
} 
  for （ var  i =  0 ; i< num.length +  1 ; i ++）{
  var  expr = exp [i  -   1 ] ==  undefined ？ ' '：exp [i  -   1  ]。 
  var  numr = num [i] ==  undefined ？ ' '：num [i]; 
  var  str = expr + numr; 
  if （i ==  0 ）
 str = '  1' 
 result = result ==  undefined  ？ ' '：result; 
 result =  eval （结果+ str）; 
} 
 返回结果; 
} 
 
  console  .log（getResult（  10 * 20/30  -  60 + 2）） //   -  51.3333  

I have one input-box in my code. From input string I get operators and operand.

If user type "10 * 20 / 30 - 60 + 2" I get the value by getElementById

So now the question is, is there any way to do this array operations in order?

I'm expecting this calculation like:

10 * 20 is 200
200 / 30 is 6.66
6.66 - 60 is -53.33
-53.33 + 2 is -51.33
So -51.33 must be final answer.

I have tried this calculation by eval() function but the answer I got is wrong. I also want to display that answer in same input box, please don't give me examples with two text-boxes.

I have described my problem as well as I can. You can see my code link which is in comment box.

Another way to explain e.g- ["10 * 2"-> answer-> "answer / 30"-> answer -> "answer - 60" -> answer -> "answer + 2" -> answer]

What I have tried:

my code link :- jsfiddle.net/archan/z3mqnxz7

解决方案

<pre> function getResult(exp) {
            exp = '1 * ' + exp;
            var parts = exp.split(' ');
            var result, num = [], exp = []; var formu = [];

            for (var i = 0; i < parts.length; i++) {
                var item = parts[i].trim();
                if (isNaN(item))
                    exp.push(item);
                else
                    num.push(item);
            }
            for (var i = 0; i < num.length + 1; i++) {
                var expr = exp[i - 1] == undefined ? '' : exp[i - 1];
                var numr = num[i] == undefined ? '' : num[i];
                var str = expr + numr;
                if (i == 0)
                    str = '1'
                result = result == undefined ? '' : result;
                result = eval(result + str);
            }
            return result;
        }

        console.log(getResult(  "10 * 20 / 30 - 60 + 2"))  //- 51.3333

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