Sort method

[miss time]

hi ,
i did Sort class and i did many method for this class such as swap ,min and sortArr. I have difficulty in solve a this static method which is; a method that returns true if the array arr is sorted, otherwise it returns false.
I start like that...
1)
public static boolean isSorted(int[] arr, int i){
for(int i=0;i< arr.length-1;i++){
if ( arr [i]>arr [i++]); return false;

}
} it is not compile and also i feel that my answer is wrong ..

2)and if I want to reverse the number for example I have 1 2 3 4 and the result should be 4 3 2 1

,so can you help me to understand this question and explain to me how to write these code

[Ganon11]

Let's keep this one question at a time, please. We'll focus on your first question:

I have difficulty in solve a this static method which is; a method that returns true if the array arr is sorted, otherwise it returns false.
I start like that...
[CODE=java]public static boolean isSorted(int[] arr, int i){
for(int i=0;i< arr.length-1;i++){
if ( arr [i]>arr [i++]);
return false;

}
}[/CODE]it is not compile and also i feel that my answer is wrong ..

OK, the function header looks good...except you are passing the integer i as an argument. Why? Especially when, in your for...loop, you create another integer i as part of the initialization process. The integer in the function header is unnecessary.

Now, your for loop looks good. It's running from i = 0 to i = array.length - 2, because you are going to be comparing an element with the next adjacent element, and you can't access arr[arr.length].

The if statement condition is wrong. i++ will take place after the > operator is checked, so you are comparing the same element to itself, then incrementing i. You also do not want to increment i inside the for loop, as your loop itself is already doing that. Instead, use i + 1 to make sure you get the next element, but don't change i. You also have a semicolon after the if statement, so the return false; statement is never reached.

Finally, you don't allow for the fact that the array may be sorted (i.e. where's the return true?).

[miss time]

Let's keep this one question at a time, please. We'll focus on your first question:



OK, the function header looks good...except you are passing the integer i as an argument. Why? Especially when, in your for...loop, you create another integer i as part of the initialization process. The integer in the function header is unnecessary.

Now, your for loop looks good. It's running from i = 0 to i = array.length - 2, because you are going to be comparing an element with the next adjacent element, and you can't access arr[arr.length].

The if statement condition is wrong. i++ will take place after the > operator is checked, so you are comparing the same element to itself, then incrementing i. You also do not want to increment i inside the for loop, as your loop itself is already doing that. Instead, use i + 1 to make sure you get the next element, but don't change i. You also have a semicolon after the if statement, so the return false; statement is never reached.

Finally, you don't allow for the fact that the array may be sorted (i.e. where's the return true?).

Thank you very much i understand what you mean and I solve it as follow:
[CODE=java]public static boolean isSorted(int[] arr){
for(int i=0;i<arr.lengt h - 1;i++){
if( arr[i] > arr[i+1] ) return false;
}
return true;
} [/CODE]
and when I compile, it work

Also i solve the second as follow:



[CODE=java]public static void reverse1(int[] arr){
int from = 0;
int to = arr.length -1;
while( from < to ){
swap(arr, from, to);
from++;
to--;
}
}[/CODE]
and when i test these number 1,2,3,4,5 I get 5,4,3,2,1
thank you again for your explain..