JavaScript using variable value as name of object method

Question

I have function with parameters method and url , where method can be equal to get , post , etc. I can do like this

var req = function(method, url) {
    if(method == 'get') {
        request.get(url, function(){...});
    }
    else if(method == 'post') {
        request.post(url, function(){...});
    }
}

or use switch . But I wonder is there any way to do it without using any condition, but calculate variable value during calling of the function?

Answer 1

只需使用括号 ：

request[method](url, function(){...});

Answer 2

In your particular case post and get are properties of the request object, so you can access them with the help of bracket notation :

if(typeof request[method] === 'function') {
    request[method](url, function(){...});
}

You can also use eval() function but it is not recommended, because it makes your code vulnerable for injection attacks, makes it harder to read and debug, and so on.