问java中使用indexOf的这一行是什么意思？

EN

// Import scanner class
import java.util.Scanner;

// Create class and method
class Main {
public static void main(String[] args) {

Scanner inp = new Scanner(System.in);
System.out.println("Press any key to start");
String key = inp.nextLine();
System.out.println("\nEnter the amount of each item");
System.out.println("Upto 5 inputs are allowed!\n");

int counter = 0;
int index = 0;
double[] numbers = new double[5];

boolean go = true;

while(go) {           
    String value = inp.nextLine();      
    
    int indexOfH = value.indexOf("h");
    boolean containsH = indexOfH == 0 || indexOfH == (value.length()-1);

    if(containsH){ //Validate h at beginning or end 
        numbers[index] = Double.parseDouble(value.replace("h", ""));
          System.out.println("HST will be taken account for this value");
    }
    counter++;
    if (counter == 5){
      go = false;
    }
}
System.out.println("Printing Valid values");

for(int i=0; i< numbers.length; i++) {
        System.out.println(numbers[i]);
    }
  }
}