在文本字段中使用Javascript运行方程式 [英] Running an equation with Javascript from a text field

问题描述

我正在尝试创建一个简单的在线计算器，该计算器可以使用Javascript运行基本计算.

I am trying to create a simple online calculator that can run basic calculations in Javascript.

我设法创建了接口，以便将数字和运算符存储在表单字段中.

I have managed to create the interface so that numbers and operators and stored in a form field.

我想做的就是将form字段中的值传递给一个函数，该函数将计算form字段的总数.

What I would like to be able to do is pass the values within the form field to a function that will calculate the total of the form field.

form字段可以包含任何内容，从简单的10 + 10到使用方括号的更复杂的方程式.使用的运算符是+-*/

The form field could contain anything from a simple 10 + 10 to more complex equations using brackets. The operators in use are +-*/

是否可以将form字段传递给javascript函数，该javascript函数可以识别运算符并执行对值的运算功能.

Is it possible to pass the form field to a javascript function that can recognize the operators and the perform the function of the operation on the values.

文本字段中的可能值为:

A possible value in the text field would be:

120/4 + 130/5

120/4+130/5

然后，该函数应返回56作为答案.当我知道类似小提琴中的值 http://jsfiddle.net/DhqGB/

The function should then return 56 as the answer. I have done this in javascript when I know the values like in this fiddle http://jsfiddle.net/DhqGB/

我想做的就是将完整的值"120/4 + 130/5"传递给该函数，它能够提取数字和运算符以创建总数.

What I would like to be able to do is pass the full value "120/4+130/5" to the function and it be able to extract the numbers and operators to create the total.

有人对如何完成甚至可能做到有任何想法吗?这可能会变得更加复杂，可能需要在括号(120/4)+(130/5)"中传递值

Does anyone have any ideas on how this could be done or if it is even possible? this may get more complex where I may need to pass values in parentheses "(120/4)+(130/5)"

推荐答案

eval有什么用?

将calc视为文本字段的ID.然后

consider calc as the id of textfield. then

$('#calc').change(function(e){                
    alert(eval($(this).val()));
})

但是请记住在处理之前先验证输入.

but remember to validate input before processing.

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