без запинки написать функцию add которая складывает a и b и вызывается так: add(a)(b)

Write the result of these expressions: 
 6 / «3» 
 «2» * «3» 
 4 + 5 + «px» 
 «$» + 4 + 5 
 «4» — 2 
 «4px» — 2 
 7 / 0 
 typeof null 
 typeof {}[0] 
 typeof («4px» — 2) 
 parseInt(«09») 
 5 && 2 
 2 && 5 
 5 || 0 
 0 || 5

console.log(6/'3')
 console.log('2'*'3')
 console.log(4+5+'px') 
 console.log('$'+4+5)
 console.log('4' - 2) 
 console.log('4px' -2)
 console.log(7 / 0) 
 console.log(typeof NaN )
 console.log(typeof {}[0] )
 console.log(typeof ('4px' - 2) )
 console.log(parseInt('09'))
 console.log(5 && 2 )
 console.log(2 && 5 )
 console.log(5 || 0 )
 console.log(0 || 5)

alert( !![] + ![] - 1  ) // ???

function add(a){
	return function(b){ 
		return a+b
	}
}
alert([
add(2)(3) //5
,6 / "3" //2
,"2" * "3" //6
,4 + 5 + "px" //'9px'
,"$" + 4 + 5 //'$45'
,"4" - 2 //2
,"4px" - 2 //NaN
,7 / 0 //Infinity
,typeof null //object
,typeof {}[0] //undefined
,typeof ("4px" - 2) //number
,parseInt("09") //хз
,5 && 2 //2
,2 && 5 //5
,5 || 0 //5
].join('\n'))

alert([(4 + 5) + "px", "px" + (4 + 5)])

var obj1 = new Object();
var obj2 = new Object;
var obj3 = {};

var x=3;
x=3;

alert(sum(3, 4));
function sum(arg1, arg2) {
    return arg1 + arg2;
}
 
alert(sum2(3, 4));
var sum2 = function(arg1, arg2) {
    return arg1 + arg2;
};

“1” + 2 + 3 = ?
1 + 2 + “3” = ?

function Something() {
   if (!Something._inst)
      Something._inst=this;
   return Something._inst;
}

var a = new Someting, b = new Someting;
 
Someting.prototype.my_name = 'Jack';
 
a === b && a.constructor === Someting && b.constructor === Someting && b.my_name == 'Jack'

function Something() {
   if (!Something._inst)
      Something._inst=this;
   return Something._inst;
}

function A () {

    var created = this;

    A = function () {
        return created;
    };

}


a = new A();
b = new A();

alert( a === b );

var Foo = function() {
   return this.constructor; // или Foo, встроенные конструкторы (Array, Date...) и т.д.
};

var a = new Foo;
var b = new Foo;

alert(a === b);