JavaScript Questions & Answers – Statements

This set of Javascript Multiple Choice Questions & Answers (MCQs) focuses on “Statements”.

1. JavaScript is a _______________ language.
a) Object-Oriented
b) High-level
c) Assembly-language
d) Object-Based
View Answer

2. What will be the output of the following JavaScript code?

var a=5 , b=1
var obj = { a : 10 }
with(obj) 
{
      alert(b)
}

a) 10
b) Error
c) 1
d) 5
View Answer

3. A conditional expression is also called a _______________
a) Alternative to if-else
b) Immediate if
c) If-then-else statement
d) Switch statement
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4. Which is a more efficient JavaScript code snippet?
Code 1 :

for(var num=10;num>=1;num--)
{
           document.writeln(num);
}

Code 2 :

var num=10;
while(num>=1)
{
       document.writeln(num);
       num++;
}

a) Code 1
b) Code 2
c) Both Code 1 and Code 2
d) Cannot Compare
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5. What is a block statement in JavaScript?
a) conditional block
b) block that contains a single statement
c) both conditional block and a single statement
d) block that combines multiple statements into a single compound statement
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6. When an empty statement is encountered, a JavaScript interpreter __________
a) Ignores the statement
b) Prompts to complete the statement
c) Throws an error
d) Shows a warning
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7. The “var” and “function” are __________
a) Keywords
b) Declaration statements
c) Data types
d) Prototypes
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8. In the following switch syntax, the expression is compared with the case labels using which of the following operator(s)?

switch(expression)
{
    statements
}

a) ==
b) equals
c) equal
d) ===
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9. What happens in the following javaScript code snippet?

var count = 0;
while (count < 10) 
{
     console.log(count);
     count++;
}

a) The values of count are logged or stored in a particular location or storage
b) The value of count from 0 to 9 is displayed in the console
c) An error is displayed
d) An exception is thrown
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10. The enumeration order becomes implementation dependent and non-interoperable if ___________
a) If the object inherits enumerable properties
b) The object does not have the properties present in the integer array indices
c) The delete keyword is never used
d) Object.defineProperty() is not used
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11. What will be the output of the following JavaScript code?

let a = 1;
if (a > 10) {  
    document.write(10);  
} else {
    document.write(a > 10);  
}

a) 10
b) 0
c) 1
d) false
View Answer

12. What will be the output of the following JavaScript code?

var B = 65; // ASCII value of A
var grade = B;
var result = 0; // Initialize result here
switch(grade) {
    case 'A': {
        result += 10; 
        break;
    } 
    case 'B': {
        result += 9;
        break;
    }  
    case 'C': {
        result += 8;
        break;
    }  
    default:  
        result += 0;  
}  
document.write(result);

a) 74
b) 75
c) 73
d) 0
View Answer

13. What will be the output of the following JavaScript code?

var grade='A';  
var result=0;  
switch(grade)
{  
    case 'A':  
        result+=10;  
    case 'B':  
        result+=9;  
    case 'C':  
        result+=8;  
    default:  
        result+=0;  
}  
document.write(result);

a) 10
b) 27
c) 8
d) 0
View Answer

14. What will be the output of the following JavaScript code?

var a = 4;
var b = 1;
var c = 0;
if (a === b)
    document.write(a);
else if (a === c)
    document.write(a);
else
    document.write(c);

a) 4
b) 1
c) Error
d) 0
View Answer

15. What will be the output of the following JavaScript code?

var grade='C';  
var result = '';  
switch(grade)
{  
    case 'A':  
        result+=" 10";  
    case 'B':  
        result+=" 9";  
    case 'C':  
        result+=" 8";  
    default:  
        result+=" 0";  
}  
document.write(result);

a) 8
b) 9
c) 10
d) None of the mentioned
View Answer

Sanfoundry Global Education & Learning Series – Javascript Programming.