How can I obtain the first character of a string that is given by a user input in java-CodePudding

I want the user to input a String, lets say his or her name. The name can be Jessica or Steve. I want the program to recognize the string but only output the first three letters. It can really be any number of letters I decide I want to output (in this case 3), and yes, I have tried

charAt();

However, I do not want to hard code a string in the program, I want a user input. So it throws me an error. The code below is what I have.

        public static void main(String args[]){

         Scanner Name = new Scanner(System.in);
        
        
        System.out.print("Insert Name here ");
        System.out.print(Name.nextLine());
        System.out.println();
        
        
        for(int i=0; i<=2; i  ){

            System.out.println(Name.next(i));
            
        }
        
        }

the error occurs at

System.out.println(Name.next(i)); it underlines the .next area and it gives me an error that states,

"The Method next(String) in the type Scanner is not applicable for arguments (int)"

Now I know my output is supposed to be a of a string type for every iteration it should be a int, such that 0 is the first index of the string 1 should be the second and 2 should be the third index, but its a char creating a string and I get confused.

CodePudding user response：

 System.out.println("Enter string");
            Scanner name = new Scanner(System.in);
            String str= name.next();
            System.out.println("Enter number of chars to be displayed");
            Scanner chars = new Scanner(System.in);
            int a = chars.nextInt();
            System.out.println(str.substring(0, Math.min(str.length(), a)));

CodePudding user response：

When you take entry from a User it's always a good idea to validate the input to ensure it will meet the rules of your code so as not to initiate Exceptions (errors). If the entry by the User is found to be invalid then provide the opportunity for the User to enter a correct response, for example:

Scanner userInput = new Scanner(System.in);
    
String name = "";
// Prompt loop....
while (name.isEmpty()) {
    System.out.print("Please enter Name here: --> ");
    /* Get the name entry from User and trim the entry
       of any possible leading or triling whitespaces.  */
    name = userInput.nextLine().trim();
        
    /* Validate Entry...
       If the entry is blank, just one or more whitespaces, 
       or is less than 3 characters in length then inform
       the User of an invalid entry an to try again.     */
    if (name.isEmpty() || name.length() < 3) {
        System.out.println("Invalid Entry ("   name   ")!\n"
                  "Name must be at least 3 characters in length!\n"
                  "Try Again...\n");
        name = "";
    }
}
    
/* If we get to this point then the entry meets our
   validation rules. Now we get the first three 
   characters from the input name and display it.  */
String shortName = name.substring(0, 3);
System.out.println();
System.out.println("Name supplied: --> "   name);
System.out.println("Short Name:    --> "   shortName);

As you can see in the code above the String#substring() method is used to get the first three characters of the string (name) entered by the User.