Write a program in java to check string is identifier or not

Question

Help.....

Answer 1

I like the fact that you like your own question and your own answer so much that you upvoted it and gave yourself the best answer, but that's not what the Q&A section is for. Please use the Q&A section only if you actually have a question or want to answer other people's (!) questions.

https://www.sololearn.com/discuss/1316935/?ref=app

Answer 2

The problem lies within the `if` block, here's a fixed version of the `if` block with a little comment to explain the problem. Hope it helps.

if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c == '_') || (c == '#x27;))
{
// 1st character is good, increment <count>
count++;
// for(int i=1;i <= l;i++)
// i <= l : index out of bounds
for(int i = 1; i < l; i++)
{
// check variable <c>, not <l>
c = s.charAt(i);
// if((l >= 'a' && l <= 'z') || (l >= 'A' && l <= 'Z') || (l >= '0' && l <= '9') || (l == '_') || (l == '#x27;))
if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || (c == '_') || (c == '#x27;))
{
count++;
}
}
if(count == s.length())
{
flag=false;
}
}
else
{
flag=true;
}

Answer 3

Hi Mohammad Umair It would help to save this code in Code Playground, then post a link here for others to review. Also, since you've marked your question as answered, you may not get many replies. I recommend removing the green checkmark next to your answer so others know this question is still unresolved.

Answer 4

import java.util.*;
class identi
{
public static void main(String arg[])
{

System.out.print("Enter a character:");
Scanner sc=new Scanner(System.in);
String s;
int count=0;
boolean flag = false;
s=sc.nextLine();
int l=s.length();
char c=s.charAt(0);

if( (c>='a'&& c<='z')||(c>='A'&& c<='Z')||(c=='_')||(c=='#x27;))
{
for(int i=1;i<=l;i++)
{
if((l>='a'&& l<='z')||(l>='A' && l<='Z')||(l>='0'&& l<='9')||(l=='_')||(l=='#x27;))
{
count++;
}
}

if(count==s.length())
{
flag=false;
}
}

else
{
flag=true;
}

if(flag==false)
System.out.println("It is a valid identifier");
else
System.out.println("It is not a valid identifier");

}
}

Answer 5

my code not running right