JavaScript Questions & Answers – Defining and Invoking Functions

This set of Javascript Multiple Choice Questions & Answers (MCQs) focuses on “Defining and Invoking Functions”.

1. The function definitions in JavaScript begins with _____________
a) Identifier and Parentheses
b) Return type and Identifier
c) Return type, Function keyword, Identifier and Parentheses
d) Identifier and Return type
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2. What will be the output of the following JavaScript code?

function printprops(o) 
{
    for(var p in o)
      console.log(p + ": " + o[p] + "\n");
}

a) Prints the contents of each property of o
b) Returns undefined
c) Prints only one property
d) Prints the address of elements
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3. When does the function name become optional in JavaScript?
a) When the function is defined as a looping statement
b) When the function is defined as expressions
c) When the function is predefined
d) when the function is called
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4. What is the purpose of a return statement in a function?
a) Returns the value and continues executing rest of the statements, if any
b) Returns the value and stops the program
c) Returns the value and stops executing the function
d) Stops executing the function and returns the value
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5. What will happen if a return statement does not have an associated expression?
a) It returns the value 0
b) It will throw an exception
c) It returns the undefined value
d) It will throw an error
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6. A function with no return value is called ___________
a) Procedures
b) Method
c) Static function
d) Dynamic function
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7. The function stops its execution when it encounters?
a) continue statement
b) break statement
c) goto statement
d) return statement
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8. Which keyword is used to define the function in javascript?
a) void
b) int
c) function
d) main
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9. Which is an equivalent code to invoke a function m of class o that expects two arguments x and y?
a) o(x,y);
b) o.m(x) && o.m(y);
c) m(x,y);
d) o.m(x,y);
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10. What will be the equivalent code of the following JavaScript code?

o.m(x,y);

a) o.m(x) && o.m(y);
b) o[“m”](x,y);
c) o(m)[“x”,”y”];
d) o.m(x && y);
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11. What will be the output of the following JavaScript code?

function info()
{  
    int a=1;
    int b=2;
    return a*b;  
}  
document.write(info());

a) 1
b) 2
c) 3
d) error
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12. What will be the output of the following JavaScript code?

var arr = [7, 5, 9, 1];  
var value = Math.max.apply(null, arr);  
document.writeln(value);

a) 7
b) 5
c) 1
d) 9
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13. What will be the output of the following JavaScript code?

var person = 
{  
      name: “Rahul”,  
      getName: function() 
      {  
          nreturn this.name;  
      }  
} 
var unboundName = person.getName;  
var boundName = unboundName.bind(person);  
document.writeln(boundName());

a) runtime error;
b) compilation error
c) Rahul
d) undefined
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14. What will be the output of the following JavaScript code?

function code(id,name) 
{  
  		this.id = id;   
  		this.name = name;  
}  
function pcode(id,name) 
{  
 		code.call(this,id,name);  
}
document.writeln(new pcode(101,"vivek").id);

a) vivek
b) 101
c) Runtime error
d) Compilation error
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15. What will be the output of the following JavaScript code?

     var pow=new Function("num1","num2","return Math.pow(num1,num2)");  
     document.writeln(pow(2,3));

a) 2
b) 3
c) 8
d) error
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Sanfoundry Global Education & Learning Series – Javascript Programming.