Doubt

Question

System.out.println(“hello123”.replaceAll(“a-z”,””);
Output is :hello123

Why? Iam not understanding
I want 123 as my output instead it is getting hello123 even after replace method... why?

Answer 1

\\D is regex for non-digit char
[a-z] is regex for char from a-z group of chars

Answer 2

Hello There Haritha. You are a bit wrong there. Here's the corrected code :

System.out
.println("hello123".replaceAll("[a-z]", ""));

However, if you want to remove the Capital Letters too then you should write the following :

System.out
.println("hello123".replaceAll("[A-Za-z]", ""));

Answer 3

or
"hello123".replaceAll("\\D","")

Answer 4

zemiak i didnt understood ur concept
what is (“\\D”,””)mean

Answer 5

Arb Rahim Badsa grt explaination thank you