Accessing last Index through substring and also with charAt but getting error in charAt()

Question

For example I have one String="something" now if I will access the last index(str.length()) of this string it will give "String index out of range: -1". But If I access this through Substring it does not give any error.

String str="something" str.charAt(9); Run time Error || Str.substring(9); No error and it will not print anything.

Please Help

Answer 1

The String#substring documentation mentions (emphasis mine) it clearly

Throws:

IndexOutOfBoundsException - if beginIndex is negative or larger than the length of this String object .

Answer 2

Index will start from 0 and ends at length-1 .

In order to access the last character, you have to call the charAt function with length-1.

String str = "something";
str.charAt(str.length() - 1);

this will give g as result.

Answer 3

Please check the documentation of both the methods you will get an idea. Both of your use cases are mentioned in the exception section. https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#charAt(int) https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#substring(int)