What will be the output of the below code segment?

var input = "1234-5678-9012-3456-7890";

alert(input.substring(0,7) + input.substring(7,15).replace(/\d/g, "*") + input.substring(15));

The

input.substring(0,7)

will return 1234-56

The

input.substring(7,15)

will return 78-9012- ad then by using the

replace(/\d/g, "*")  

we are replacing the digits by *. so the code segment

input.substring(7,15).replace(/\d/g, "*")

will return **-****- . And then the code segment

input.substring(15)

returns 3456-7890 .Hence the final output will be 1234-56**-****-3456-7890