In anticipation of the start of the "React.js Developer" course , we invite future students and everyone who wants to watch an open webinar on the topic "Writing an application in React + Redux".
Now we propose to pass the JavaScript knowledge quiz.
JavaScript? ?
10 JavaScript. , , . , - . .
1. ?
var bar = null;
console.log(typeof bar === "object");
a) false
b) true
c) null
d)
2. ?
(function(){
var a = b = 3;
})();
console.log("a defined? " + (typeof a !== 'undefined'));
console.log("b defined? " + (typeof b !== 'undefined'));
a) true, false
b) false, true
c) true, true
d) false, false
3. React ____ .
a)
b)
c)
d)
4. React?
a) componentWillMount
b) JavaScript
c) componentDidMount
d) Facebook
5. Babel?
a)
b)
c)
d)
6. DOM?
a) HTML- DOM
b)
c) JavaScript,
d) JSON, , react.render
7. DOM?
a) DOM , DOM.
b) - , DOM.
c) DOM — .
d) DOM .
8. ?
useLayoutEffect
React- , .
9. JavaScript?
a) default
b) throw
c) finally
d) undefined
10. ?
function foo1() {
return {
bar: 'hello'
};
}
function foo2() {
return
{
bar: 'hello'
};
}
a) undefined
, { bar: “hello” }
b) { bar: “hello” }
, undefined
c) undefined
, undefined
d) { bar: “hello” }
, { bar: “hello” }
1
b) , null
. typeof
, null
.
2
b) b
, a
— . b = 3; a = undefined
. , (use strict
).
3
b) React — .
4
a) , . .
5
d) , Babel , . , .
6
c) DOM — JavaScript, , DOM.
7
a) . , .
8
. useEffect
.
9
d) undefined
, .
10
b) return
, .
, . - — ! , - .
"React.js Developer".
" React+Redux".
