Evaluate string as a conditional statement

问题

I am working on a c++ web-based IDE for beginners where one of it's core function is to let the user know the evaluation result (true or false) of the conditional statement they have on my contenteditable div.

Say i am already able to fetch the "fragment" (what i call it based on my architecture) that i wanted to evaluate and i already know the values of the variables...

Can you please suggest a way on how would i evaluate the text on the fragment as a conditional statement that will return either true or false...

Example

when var b = 5;

$('.frag').eq(1).text() //"if( (b>1) || (b==10) )"

after evaluation(what im asking for help) should return true

 $('.frag').eq(2).text() //"(b>1)" 

should return true

 **$('.frag').eq(3).text() //"(b==10)"

should return false

UPDATE

The problem i am seeing with eval is that if i have a var1 in the contenteditable div and i have a var1 in my code. I should put a header on the variables from the contenteditable then right? like sc_var1 to prevent messing up with var1 from my source code?

回答1:

You can use Eval like this:

var expression = $('.frag').eq(1).text();
var result = eval(expression);

However I generally do not recommend using eval because there is always a much better workaround.

if I get the bigger picture of your needs I would be able to provide a better solution.

来源：https://stackoverflow.com/questions/18842283/evaluate-string-as-a-conditional-statement