Q. What will be the output of the following Javascript code?
Code:
var str1 = ”4321”; var intval = 4321; alert( str1 + intval );
✅ Correct Answer: (B)
43214321
Explanation:
In the given code:
var str1 = "4321"; // string
var intval = 4321; // number
alert( str1 + intval ); // concatenates str1 and intval
The key point here is that JavaScript uses type coercion when you perform the + operation between a string and a number. Since one of the operands (str1) is a string, JavaScript converts the other operand (intval) to a string as well. Then, the two strings are concatenated.
- str1 is the string "4321".
- intval is the number 4321, which is coerced into the string "4321".
When these two strings are concatenated:
"4321" + "4321" => "43214321"
Thus, the output of alert(str1 + intval) will be the string "43214321".
Why the other options are incorrect:
- (A) 4321: This is incorrect because it would require a mathematical operation, not string concatenation.
- (C) 8642: This would happen if we were performing arithmetic addition, but the + operator here is used for string concatenation.
- (D) 12341234: This is incorrect because it's not related to the given values or any possible operation with those values.
So, the correct output is (B) 43214321.