JavaScript: Problems added in December 2015

complexity: 4 ; importance: 2; author: docentmail

Question: What world would be the result for each line?

typeof "John";
typeof 3.14;
typeof false;
typeof [1,2,3,4];
typeof {name:'John', age:34};

complexity: 1 ; importance: 7; author: docentmail

Question: What should be placed instead of dots to have method do (); performed only when x does not equal y ?

if (x ... y) {
  do();
}

complexity: 1 ; importance: 7; author: docentmail

Question: What is the name of "=" operators ?

complexity: 2 ; importance: 6; author: docentmail

Question: Give a code fragment that declares a variable, but is not initializing it.

complexity: 2 ; importance: 3; author: docentmail

Question: is this a valid JS statement?

var x= "Hello", cat= "Bob", height = 20;

complexity: 2 ; importance: 3; author: docentmail

Question: replace the statement

var x= "Hello", cat= "Bob", height = 20;

complexity: 2 ; importance: 8; author: docentmail

Question: Is this valid JavaScript code?

var x= "Hello";
x=[1,2,3];
x=5;

complexity: 3 ; importance: 6; author: docentmail

Question: Use switch statement and write the code that alert Today is your day!

complexity: 1 ; importance: 2; author: docentmail, 4luckynikita

Question:Name this char '

complexity: 1 ; importance: 5; author: docentmail, 4luckynikita

Question:Name the main four arithmetical operations.

complexity: 1 ; importance: 2; author: docentmail, 4luckynikita

Question:Assign number value to variable

complexity: 1 ; importance: 3; author: 4luckynikta

Question:How can you define the text John Doe as a string

complexity: 2 ; importance: 5; author: 4LUCKYNIKITA

Question: What would the alert say?

x=5
x += 5 + 2 
alert ( x ) ;

complexity: 1 ; importance: 3; author: docentmail

Question: Give two variants how to access "name" property of given cat object.

var cat = {name:"Peter", hi:function() {alert("Hello my friend");}}

complexity: 3 ; importance: 6; author: docentmail

Question: create object that has a "name" field and can alert text "Hello my friend" on calling his hi method

complexity: 2 ; importance: 5; author: docentmail

Question: What would be value of x?

var x = 100 / "10";

complexity: 2 ; importance: 5; author: docentmail

Question: What would be value of x?

var x = 100 / "Apple"; 

complexity: 2 ; importance: 2; author: docentmail

Question: What will return typeof x; and typeof y;?

var x = 123;
var y = new Number(123);

complexity: 2 ; importance: 2; author: docentmail

Question:Give two different approaches to create an array

complexity: 2 ; importance: 4; author: docentmail

Question: How to assign last element of array b to var x

complexity: 2 ; importance: 2; author: docentmail

Question: Where is a literal in the expression?

var x = 5;

complexity: 5 ; importance: 1; author: docentmail

Question: What would be result of execution of expresion?

typeof typeof 123 
   or the same with parenthis 
     typeof(typeof(123))

complexity: 5 ; importance: 2; author: docentmail

Question: how many times method do() would be called?

for (i = 0, j=3; i < j; i++,j-- ) { 
   do();
}

complexity: 2 ; importance: 4; author: docentmail

Question: how many times method do() would be called?

for (i = 0; i > 1 ; i++) { 
   do();
}

complexity: 2 ; importance: 4; author: docentmail

Question: how many times method do() would be called?

for (i = 0; i < 1 ; i) { 
   do();
}

complexity: 2 ; importance: 5; author: docentmail

Question: how many times method do() would be called?

for (i = 0; i < 1 ; i++) { 
   do();
}

complexity: 3 ; importance: 5; author: docentmail

Question: Replace with the code fragment, with equals one that only one “.” per line/statement

var rez = document.getElementById("testspan").getAttribute("class").length;

complexity: 2 ; importance: 2; author: docentmail

Question: What is the purpose of typeof operator?

complexity: 2 ; importance: 2; author: docentmail

Question: Question: What will "x" equal?

var x = 16 + 4 + "Volvo";

complexity: 2 ; importance: 2; author: 4luckynikita, rorp32, DogeLover1337, TimberWolf91

Question: Question: What will "x" equal?

var x = "Volvo" + 16 + 4;

complexity: 1 ; importance: 3; author: 4luckynikita

Question: Which of the following lines are correct?

var x = 5; 
var x = // my comment   5 ;
var x = 5; // my comment
var x = 5 // my comment   ;
// var x = 5; 

complexity: 2 ; importance: 2; author: docentmail

Question: what does alert (x[1]); show?

var x = [1,2,3];
var y = x;
y[1]=100;
alert (x[1]);

complexity: 2 ; importance: 4; author: docentmail

Question: what does alert (x); show?

var x = 1;
var y = x;
y=101;
alert (x);