Question

Consider the following code:

    if(eform[funcName] !== undefined){
        if(eform[funcName].init !== undefined){
            //finally do something
        }
    }

I’m first checking to see if the eform object has the property specified by the variable funcName. If it does, then I need to check whether that property has an init method.

Is there any way to combine these into a single if statement? Or perhaps something even more elegant than that?

Answer 1

Using Short-Circuit evaluation:

if (eform[funcName] !== undefined && eform[funcName].init !== undefined)

If eform[funcName] is undefined the statement if false and eform[funcName].init is never checked. Depending on preference/readability this following is vaild as well:

if (eform[funcName] && eform[funcName].init)