jQuery.isPlainObject

Question

isPlainObject: function( obj ) {
        var proto, Ctor;

        // Detect obvious negatives
        // Use toString instead of jQuery.type to catch host objects
        为什么要代替呢
        if ( !obj || toString.call( obj ) !== "[object Object]" ) {
            return false;
        }

        proto = getProto( obj );

        // Objects with no prototype (e.g., `Object.create( null )`) are plain
        if ( !proto ) {
            return true;
        }

        // Objects with prototype are plain iff they were constructed by a global Object function
        Ctor = hasOwn.call( proto, "constructor" ) && proto.constructor;
        return typeof Ctor === "function" && fnToString.call( Ctor ) === ObjectFunctionString;
    },

toString instead of jQuery.type?

Answer 1

等待大神解答