Test
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Preguntas del test (46)
1Please select all correct variants of connection the external JavaScript file:
- A<link rel="stylesheet" href="script.js">
- B<script src="script.js"></script>
- C<script defer src="script.js"></script>
- D<script></script>
2Select all correct variants of variable declaration:
- Avar t = 'Hello))';
- Blet _c = document.body;
- Cvar 1c = 56;
- Dlet $ = true;
- Elet obj = {};
3Is the statement "JS is a dynamically typed language" true?
- AVerdadero
- BFalso
4Which data type is better to use to create unique values?
- ANumber
- BBigInt
- CSymbol
- DString
5What statement is correct to create a variable of BigInt type?
- Alet a = 123;
- Blet a = 123n;
- Clet a = '123n';
- Dlet a = BigInt(123);
6What is the result of executing the typeof operator in the below code?
let myVar;
typeof myVar;- Anull
- Bundefined
- C"undefined"
- D"null"
7Choose the right variant for accessing an object property:
- Astudent.name;
- Bstudent->name
- Cstudent[name]
- Dstudent["name"]
8How does the data type in JS affect the variable?
- ADefines a range of valid values
- BDefines a set of operations on a variable
- CAllows to check the type of a variable during the code compilation time
- DSpecifies how a variable is stored in memory
9What is output of the code below?
console.log(null==undefined)- AVerdadero
- BFalso
10What outputs to the console after executing the code?
let a = "75";
let b = "75a";
console.log(Number(a));
console.log(Number(b));- A75 75
- BNaN NaN
- C75 ReferenceError
- D75 NaN
11What is output to the console of the code execution?
let a=5;
let b=7;
let c=a+++b;
console.log(a,b,c);- A6 7 12
- B5 7 12
- C5 8 13
- D6 7 13
- E6 8 14
12What is output to the console of the code execution?
console.log(!1 && undefined && 'test');- Afalse
- B0
- C-1
- Dtest
- Etrue
13What is the output of this code?
console.log(7 % (4 || !1));- A0
- B1
- C2
- D3
- Etrue
- Ferror
14Select all the expressions that return true
- A!!'false' === !!'true'
- Btrue + true
- C0.2+0.7 == 0.9
- D3 > 2 > 1
- Enull >= 0
- Fnull > 0
- Gtrue=="true"
- H0.2 + 0.6 == 0.8
15Put the result of the operation
+("165"+"1") + 10- A1661
- B"165110"
16Choose the right conditional constructs:
- Aif (a==3) then alert('Hello')
- Bif (a==3) alert ('Hello')
- Cif (a==3) {alert ('Hello')}
17What is output to the console?
var b = 10;
if (b % 3 == 0) {
var i = 10;
}
console.log(i);- AError
- BNumber 10
- CNaN value
- DEmpty string value
- Eundefined value
18Is the "else" element required in the conditional construct?
- AYes
- BNo
- CDepends on JavaScript version
- DDifferent in different browsers
19What is a conditional operator?
- AA construct that executes code multiple times
- BConstruct for creating a specific variable
- CConditional branching
20What is the correct way to use the operator IF in JavaScript?
- Aif i == 2 then
- Bif (i == 2){}
- Cif i = 2 then {}
- Dif i = 2{}
21What is stored in the variable?
var a = 5;
var test = 5 == a ? "Yes" : "No";- A"Yes"
- BNo
- C5
- DYes
- Eundefined
22What is output when executing the following code?
var a = false;
if (a == `0`) {
alert(`==`);
}
if (a === `0`) {
alert(`===`);
}- ANothing
- B===
- C==
- D== and ===
23What is output to the console?
- Aundefined
- B"Hello"
- CSyntaxError
- D"Error"
24What value is output in the console?
- A6
- B9
- C7
- DSyntaxError: Wrong default clause in swich statement
- ESyntaxError: More then one sreak clause in swich statement
- F8
- G12
25What is output of the code below?
alert( null || 2 || undefined );- Anull
- B2
- Cundefined
26What is output of the code below ?
var x = 3;
{
var x = 5;
}
console.log(x);- A3
- B4
- C5
27Choose a condition IF to test the fact that age is between 14 and 90 included:
- Aif (age > 14 && age < 90)
- Bif (age >= 14 && age <= 90)
- Cif (age >= 14 || age <= 90)
28How to describe a loop FOR correctly?
- Afor (i <= 10; i++){}
- Bfor i = 1 to 10 {}
- Cfor (i = 0; i <= 10; i++){}
- Dfor (i = 0; i <= 10){}
29What outputs to the console after executing the code?
for(let i=0; i<10; ) {
i++;
}
console.log(i);- Aundefined
- B9
- C10
- DReferenceError
30Which of these loops doesn't exist?
- Afor(var i = 0; i < 3; i++) {}
- Bfor(var key in object) {}
- Cwhile(true) do{}
- Dwhile(true) {}
- Edo{} while(true)
31What is output to the console of the code execution?
for(var i=0; i<10; ) {
i++;
}
console.log(i);- Aundefined
- B9
- C10
- DReferenceError
32What is a correct description of WHILE loop?
- Awhile i = 1 to 7
- Bwhile (i <= 7; i++){}
- Cwhile (i <= 7){}
33What is the output of this code?
for(let i=0; i<3; i++){
console.log(i);
}- AThe result is an error
- B0 1 2
- C1 2 3
34How many times is the code executed?
for(var i = 10; i < 35; i += 5) {
console.log(i);
}- A5
- B6
- C10
35 Which of the followings is not a correct expression for a loop in JavaScript?
- Avar i = 0;
while (i < 5) {
i++;
} - Bvar i = 0;
while (true) {
i = i;
} - Cvar i = 0;
do {
i++;
} while (i < 5); - Dvar i = 0;
while (i < 5) do {
i++;
}
- Avar i = 0;
36How many times is this loop executed?
for (var i = 0; i > -10; i-=3) {
i++;
}- A0
- B1
- C2
- D5
- E10
37What is the last output value of this code?
var i = 3;
while (i) {
alert( i‐‐ );
}- A1
- B2
- C3
- DInfinite loop
- E0
38What values of i does the while loop output?
var i = 0;
while (i++ < 5) {alert( i );}- A0,1,2,3,4
- B1,2,3,4
- C1,2,3,4,5
- Derror
39When the continue without a label is used, it breaks the current iteration of the while, do-while, and for loops and continues the loop:
- Afrom the beginning of the loop
- Bfrom the next iteration
- Cterminates the loop
40Which of the following is the correct syntax to create a function?
- Afunction foo() {}
- Bfunction foo(a) {}
- Cvar a = function(){}
- Dall of the above
41What type of function can be called before it is declared?
- AFunction declaration
- BFunction expression
- Call of the above
42What is the name of the following function type?
var sum = (a, b) => a + b;- AFunction declaration
- BFunction expression
- CArrow function
43What is output to the console in 2 line?
var f = function printLog() {
console.log('My function');
}
f;- ASyntaxError
- Bnothing
- C'My function'
- Df
44What is output to the console?
function showName(firstName='John', secondName='Doe') {
console.log(firstName, secondName);
}
showName("Robert");- AJohn Doe
- Bnothing
- CRobert Doe
- DRobert
45What is output to the console?
- ANaN
- B7
- C6
- DSyntaxError
46What is output to the console?
function sum(a, b){
a + b;
}
let result = sum(2, 5);
console.log(result);- A7
- Bundefined
- C0
- DRuntime error
Información
- Descripción
- Test sobre js, creado por vernona pit el 28/08/2022.
- Autor
- vernona pit
- Idioma
- English
- Visitas
- 1
- Valoración
- Aún sin valoraciones Valora este test