What will be alerted??

Question

var a='7';
var b='9';
alert(a+b %7);

//Answer is 72

Does anyone know how the answer came about?

Answer 1

Because
b='9';
b%7='9'%7=2 (type of number)

a='7';
a+b%7 (b%7= 2)
'7'+2= ' 72' (type of string)

//type of your output is string