What's wrong with my first program? I made an add script but someway it doesn't work

Question

I tried to make an add function but it just treat the numbers like letters.
ex: 1+1= 11
there's what I have made:

var number1=prompt('please enter a number')
var number2=prompt('please enter the number to add')
alert(number1+number2)

Answer 1

prompt return a string not a number you have to use Number() function. like
number1 = Number(number1);

var number1=prompt('please enter a number')
var number2=prompt('please enter the number to add')
number1 = Number(number1);
number2 = Number(number2);
alert(number1+number2);

You can also use

alert(eval(number1+'+'+number2));

Answer 2

u will have to convert those to numbers first and then add them using parseInt() funⁿ.

The parseInt() function parses a string and returns an integer.

parseInt(num); // default way (no radix) parseInt(num, 10); // parseInt with radix (decimal)

eg: var a = parseInt("10") + "<br>";

The radix parameter is used to specify which numeral system to be used, for example, a radix of 16 (hexadecimal) indicates that the number in the string should be parsed from a hexadecimal number to a decimal number.

If the radix parameter is omitted, JavaScript assumes the following:

If the string begins with "0x", the radix is 16 (hexadecimal)If the string begins with "0", the radix is 8 (octal). This feature is deprecatedIf the string begins with any other value, the radix is 10 (decimal)

Note: Only the first number in the string is returned!

Note: Leading and trailing spaces are allowed.

Note: If the first character cannot be converted to a number, parseInt() returns NaN.