checking for is letter in a string

Question

I am asking for user input in a string and i want to check for is alpha or numeric but i am new to java. this is what i have so far

Scanner scanner = new Scanner(System.in);
String s = scanner.nextLine();

isletter(s);  // a call to the function


 // function
public void isletter(String s)
{

for (int i = 0; i < s.length(); i++)
    if (isLetter(s.charAt(i) ) ) {

  System.out.println("is alpha = " + s);
}

else{


}


}

Here is the error i am getting when trying to compile through dos

c:\programming>javac LexemesTokenizer4.java
LexemesTokenizer4.java:62: non-static method isletter(java.lang.String) cannot b
e referenced from a static context
isletter(s);
^
LexemesTokenizer4.java:71: non-static method isletter(java.lang.String) cannot b
e referenced from a static context
isletter(s);
^
LexemesTokenizer4.java:85: cannot find symbol
symbol  : method isLetter(char)
location: class LexemesTokenizer4
        if (isLetter(s.charAt(i) ) ) {
            ^
3 errors

c:\programming>

I know this is an easy fix?

Solution 1

In isLetter, L should be lowercase. (l).

if (isLetter(s.charAt(i) ) )
   // ^ lowercase 

Keeping that mistake aside, why are you recursively calling the method isletter in the loop.

Solution 2

Maybe you mean to use the isLetter() method of the Character class like this:

 if(Character.isLetter(s.charAt(i))){

  }

Solution 3

Instead of Scanner scanner = new Scanner(System.in); on the top you should import a scanner using this: import java.util.Scanner; on the very top.

Comments

[rlc]

to wit: the L in if (isLetter(s.charAt(i) ) ) {