I made a java program to count the number of vowels in a string, and I need to use a, or multiple, for loop(s) to do it for a project. The problem is that it does not do anything, or just takes too long, after inputting the string:
import java.util.Scanner;
class Main
{
public static void main(String[] args)
{
Scanner s = new Scanner(System.in);
System.out.print("Enter a string to count the vowels>> ");
String x = s.nextLine();
int numVowels = countVowels(x, "aeiou");
System.out.println(numVowels);
}
static int countVowels(String x, String vowels)
{
int count = 0;
String z = x.toLowerCase();
for (int i = 0; i <= vowels.length() - 1; i )
{
if (i == vowels.length() - 1)
{
for (int n = z.indexOf(vowels.substring(i)); n != -1; count )
{
z.replace(vowels.substring(i), "");
}
}
else if (z.indexOf(vowels.substring(i, i 1)) != -1)
{
for (int n = z.indexOf(vowels.substring(i, i 1)); n != -1; count )
{
z.replace(vowels.substring(i, i 1), "");
}
}
}
return count;
}
}
I have reduced the number of loops, because the original was very confusing. I think the problem is with the nested loops, but I have not yet tried running this on a local compiler, only online IDEs. I've heard that it makes a world of difference for compile times.
CodePudding user response:
It's an infinite loop: you're not doing anything with z
if you use only z.replace
. Since strings are immutable in Java, you can't change it by only calling a method, you must assign it again:
z = z.replace(...)
CodePudding user response:
I took the liberty of using while-loop instead of for-loop since the idea is to keep looping till find, count and replace all the vowels one by one.
static int countVowels(String x, String vowels)
{
int count = 0;
String z = x.toLowerCase();
for (int i = 0; i <= vowels.length() - 1; i )
{
String vowel = Character.toString(vowels.charAt(i));
while (z.indexOf(vowel) != -1){
count ;
z = z.replaceFirst(vowel, "");
}
}
return count;
}