Find max value in ArrayList Java
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I am writing a program for school and I can't figure out how to get the max value in a column. I need to find the highest Sales value in the ArrayList. I don't have a fixed number of Names so there could be 2 or 10 Salespersons Name,Sales in the arraylist depending on the quantity the user inputs. After the user finishes input I need to find the highest sales value so I can output each salesperson and display how much they need to meet or exceed the highest sales. Here is how I get the data into the ArrayList: ArrayList list.add(new Salesperson(myName,mySales)); The Salesperson class/constructor is setup like this: private static class Salesperson{ private String name; private double Sales; public Salesperson(String n, double s){ this.Name = n; this.Sales = s; } }
Best Answer
Tabasco
OP
Joseph2982
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::Smacks forehead:: It's an ArrayList, not an Array. Let's try angle brackets. Java
double max = 0;
for(int i = 0; i < list.size(); i++)
if(list<i>.getSales() > max)
max = list<i>.getSales();
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9 Replies· · ·
Tabasco
OP
Joseph2982
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The length member variable should give you what you need. If not, try the size() member function. Java
double max = 0;
for(int i = 0; i < list.length; i++)
if(list[i].Sales > max)
max = list[i].Sales;
2
· · ·
Tabasco
OP
RyanAZ
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Thanks for the help! I tried it and here is what I get: I get errors. "array required, but ArrayList Length wasn't an option so size() was an available option. In the IF statement max= list[i].Sales; I get illiegal character: '\ufeff' and "array required, but ArrayList
1
· · ·
Tabasco
OP
Joseph2982
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Ah! The Sales member is private. You will need to make it public or write a get() function. Best practice says, "make a get() function." There is also a mismatch with capitalization in Name member. Java
ArrayList <Salesperson> list = new ArrayList<>();
list.add(new Salesperson(myName,mySales));
// The Salesperson class/constructor is setup like this:
private static class Salesperson {
private String Name;
private double Sales;
public Salesperson(String n, double s) {
this.Name = n;
this.Sales = s;
}
public double getSales(){
return this.Sales;
}
}
double max = 0;
for(int i = 0; i < list.length; i++)
if(list[i].getSales() > max)
max = list[i].getSales();
Does it like this any better?
1
· · ·
Tabasco
OP
RyanAZ
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Below is the code. I am still getting the same errors! Java
package compcalc;
import java.util.*;
import java.text.DecimalFormat;
/**
*/
public class CompCalc
{
private static class Salesperson {
private String Name;
private double Sales;
public Salesperson(String n, double s) {
this.Name = n;
this.Sales = s;
}
public String getName(){
return this.Name;
}
public String getName(String newName){
return(this.Name = newName);
}
public double getSales(){
return this.Sales;
}
public double setSales(double newSales){
return (this.Sales = newSales);
}
}
public static void main(String[] args)
{
//create variable to store sales value
String myName;
double mySales;
int x=0;
//initialize the ArrayList
ArrayList<Salesperson> list = new ArrayList<>();
//set decimal format precision
DecimalFormat fl = new DecimalFormat("#,###,##0.00");
//create new annualClass object
annualCalc amt = new annualCalc();
//create scanner object for input
Scanner keyboard = new Scanner(System.in);
//set variables values
amt.setGoal(120000);
amt.setPayAt(80);
amt.setSal(35000);
amt.setRate(8);
amt.setAcRate(1.25);
do{
System.out.print("How many salespeople would you like to enter:");
//validate the input is a number
while (!keyboard.hasNextInt()){
System.out.println("Invaid number. Please enter a number between 1 & 10:");
keyboard.next();
}
x = keyboard.nextInt();
} while (x <= 0);
//begin prompt loop
for(int i=1; i<=x; i++){
//prompt for salesperson name
System.out.print("\nEnter Salesperson's Name: ");
myName = keyboard.next();
//prompt salesperson for annual sales amount
System.out.print("\nEnter " + myName + " Annual Sales: $");
mySales = keyboard.nextDouble();
list.add(new Salesperson(myName,mySales));
}
double max = 0;
for(int i = 0; i < list.size(); i++){
if(list[i].getSales() > max)
max = list[i].getSales();
{
//display the results from arraylist and annualCalc class
for (int index = 0; index < list.size(); index++)
{
Salesperson person = (Salesperson)list.get(index);
amt.setAmt(person.getSales());
System.out.println("\nSalesperson :" + person.getName() +
"\nSales: $" + fl.format(person.getSales()) +
"\nAnnual Salary: $" + fl.format(amt.getSal()) +
"\nCommission Earned: $" + fl.format(amt.getAmt()) +
"\nTotal Compensation: $" + fl.format(amt.getTotal()));
}
System.out.println();
}
}
1
· · ·
Tabasco
OP
RyanAZ
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BTW.. The error is in the IF statement. The for loop is okay!
1
· · ·
Tabasco
OP
Best Answer
Joseph2982
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::Smacks forehead:: It's an ArrayList, not an Array. Let's try angle brackets. Java
double max = 0;
for(int i = 0; i < list.size(); i++)
if(list<i>.getSales() > max)
max = list<i>.getSales();
1
· · ·
Tabasco
OP
RyanAZ
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I haven't tried your suggestion yet, but I did find that the illegal character was caused by copy and paste. Seemed to have carried a line character over. I retyped it and it quit complaining.
1
· · ·
Tabasco
OP
RyanAZ
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Java
double max = 0;
for(int i = 0; i < list.size(); i++){
Salesperson s = (Salesperson)list.get(i);
if(s.getSales() > max)
max = s.getSales();
}
System.out.println("The Max Value is " + max);
I was able to get the above code to work. Thank you so much for the guidance. I know to many languages already so I keep trying my VB, C, SQL, C++, C## operators and methods which is getting me in trouble.
1
· · ·
Tabasco
OP
Joseph2982
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Interesting solution. It's curious to me that a disposable variable like that did the trick. I am happy to help. Cheers!
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