void error in Arrays.sort() in java

The Arrays.sort() method has a return type of void, meaning it does not return an object/primitive, so you can't really assign the absent return value to a char[]. The array will be sorted through the reference to it (arrays are objects) passed to the method.

BTW, the same applies for Collections.sort()

See the documentation

FIX

String text1 = "check";
char c[] = text.toCharArray();
Arrays.sort(c);

Arrays.sort(); returns void you cannot assign it to an char array i.e char[]

Note that Arrays.sort does not return type.

Source code is as follows:

public static void sort(char[] a) {
    DualPivotQuicksort.sort(a);
}

If you want to sort the char array You can use the following way:

    String text1 = "hello";
    char c[] = text1.toCharArray();

    //Sort char array
    Arrays.sort(c);

    //Print [e,h,l,l,o]
    System.out.println(Arrays.toString(c));

Arrays.sort() returns void not char[]