1. Any value other than ………………… has a tostring( ) method and the result of this method is usually the same as that returned by the string( ) function.
i) number ii) null iii) boolean iv) undefined
A) i and ii only
B) ii and iii only
C) ii and iv only
D) iii and v only
2. If one operand of the + operator is a string, it converts the other one to a ………..
A) String
B) TypeError
C) Undefined
D) Number
3. The ……………… operator converts its operand to a Boolean and negates it.
A) +
B) –
C) !
D) !!
4. The ……………… method defined by the number class accepts an optional argument that specifies a radix, or base for the conversion.
A) toRadix( )
B) toBase( )
C) toString( )
D) toBase10( )
5. ………………. converts a number to a string with a specified number of digits after the decimal point.
A) toInt( )
B) toFixed( )
C) toString( )
D) toPrecision( )
6. …………… converts a number to a string with the number of significant digits you specify.
A) toInt( )
B) toFixed( )
C) toString( )
D) toPrecision( )
7. ……………… accepts an optional second argument specifying the radix of the number to be parsed.
A) ParseFloat( )
B) ParseInt( )
C) ParseNumber( )
D) ParseString( )
8. While using parseInt( ) and parseFloat( ), if the first nonspace character is not a part of a valid numeric literal, they return ………….
A) undefined
B) infinity
C) NaN
D) zero
9. The global function parseInt(“11”,2) in JavaScript returns which of the following values.
A) 2
B) 3
C) 11
D) 13
10. The global function parseFloat(“.1”) returns which of the following values.
A) 1
B) 0.1
C) 0
D) NaN
11. Wrapper classes define ………………. methods that return the wrapped primitive value.
A) ValueOf( )
B) ParseInt( )
C) ParseNumber( )
D) ParseString( )
12. If the object has a ………………. method that returns a primitive value, JavaScript converts that primitive value, JavaScript converts that primitive value to a number and returns the result.
A) ValueOf( )
B) ParseInt( )
C) ParseNumber( )
D) ParseString( )
13. If the object has a ……………. method that returns a primitive value, JavaScript converts and returns the value.
A) toInt( )
B) toFixed( )
C) toString( )
D) toPrecision( )
14. State whether the following statements about type conversion in JavaScript are True.
i) Array to number conversion relies on the toString( ) method.
ii) The + operator in JavaScript performs numeric addition but not string concatenation
iii) With toString( ) method, empty arrays convert to the empty string.
A) i and ii only
B) ii and iii only
C) i and iii only
D) All i, ii and iii
15. …………….. object was created, while converting empty string ” ” to an object in JavaScript.
A) new string (empty)
B) new string(” “)
C) string(” “)
D) new string( )
16. While converting the value to a number, if it cannot perform a meaningful conversion will result ……….. value.
A) Infinity
B) NaN
C) undefined
D) TypeError
17. In JavaScript arithmetic, if var n=1-“x”; what will be the result of n + “objects”
A) NaN objects
B) n objects
C) NaN
D) objects
18.In JavaScript, if var a=[ ]; and var b=a; what will be the result of a = = = b.
A) False
B) True
C) Undefined
D) NaN
Answers
1. C) ii and iv only
2. A) String
3. C) !
4. C) toString( )
5. B) toFixed( )
6. D) toPrecision( )
7. B) ParseInt( )
8. C) NaN
9. B) 3
10. B) 0.1
11. A) ValueOf( )
12. A) ValueOf( )
13. C) toString( )
14. C) i and iii only
15. B) new string(” “)
16. B) NaN
17. A) NaN objects
18. B) True
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