What is wrong with my code

Question

import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.print("Enter the len:");
int len = sacn.nextInt();
ArrayList<Integer>ar = new ArrayList<Integer>;
int sum = 0;

int arr[] = new int[len];
for(int i =0;i<lrn;i++) {
a[i] = scan.nextInt();
}
for(int k = 0;k<len;k++) {
for(int o;o<(k+1);o++) {
for(int u=k;u<=o;k++) {
sum = sum+arr[u];

}
ar.add(sum);

}
}
}
}

Answer 1

//Typo mistakes : in sacn, a[] but declared arr[] array

//Ravi King corrected code , removed errors.

import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.print("Enter the len:");

int len = scan.nextInt(); //you are using sacn.n..

ArrayList<Integer> ar = new ArrayList<Integer>(); //missing ()
int sum = 0;

int arr[] = new int[len];
for(int i =0;i<len;i++) {
arr[i] = scan.nextInt(); //you are using a[I] which is not declared any where
}
for(int k = 0;k<len;k++) {
for(int o=0;o<(k+1);o++) { //'o' is uninitialized, use int o=0; or what you need!
for(int u=k;u<=o;u++) { //incrementing k++ , instead of u++ so it makes infinite loop.
sum = sum+arr[u];
}
ar.add(sum);

}
}
System .out.print(ar); //for outut some : you are not printing anything so it won't output anything ..

}
}