Sorting an array

[dude]

Hi,

Suppose you have an array of words. What is the easiest way to sort and print the array alphabetically?

Thanks.

[Belal]

Hi
if u like to sort ur word array without knowing anything about sorting algorithm, it will be better for u to use the 'Arrays' class under 'java.util.Arrays'. Just import the package at the beginning of ur program and in ur code send ur array in a statement like

Arrays.sort(ur_word_array_name);

and then print the array, to get the sorted words. Remember u may have to include ArrayIndexOutOfBoundsException or NullPointerException.

Thanks
looking forward for ur reply
belal

[dude]

No, i need to sort the array using some sort algorithm. So just importing the array utility won't work. What kind of sorting algorith can i use here?

[Belal]

Hi
here is one simple sort algorithm(bubble sort), try with this and inform me

//to sort ur array with bubble sort
for(int i=0;i<T;i++) //here T is the size ur words' array
for(int j=0;j<T-1;j++)
{
if(a[j].compareTo(a[j+1])>0) //a is the name of ur array
{
temp=a[j]; //temp is a String type data
a[j]=a[j+1];
a[j+1]=temp;
}
}
//to print the array
for(int i=0;i<T;i++)
System.out.println(a[i]);


Thanks
belal

[dude]

That was very helpful. Thank you Mr. Belal. It worked! but tell me please, what does the compare.To actually do here? I suppose it's a builtin function. Also can you describe easily, what's a method, constructor?

[Belal]

dude it's good to know that my answer helped u.

here is a small suggestion for u. when u need to know abt a builtin method
u can find with a java api documentaion. hope u have that or u will collect
that for ur future guideline.

in my code the method compareTo(String s), is a method that help us to compare two string. it compares the main string(the string variable after which we r using dot(.) and this method e.g 'a[j]' in my example) with the parameter string that is passed into the compareTo() method's parenthesis. and returns negative value if main string is smaller i.e. come before the parameter string and else postive value.

when we say 'method' it means to gather similar functions or a specific funtion statements that we write using any programming language. we can identify a method seeing a pair of parenthesis '()' after a 'methodName' e.g. compareTo().......remember to use a method we have to know if there requires any parameter value or we can simply call it.
in java we define a method like-----
<format>
returnType methodName(parameterLists or empty if no parameter)
{
//required statements
}
<end of format>
<example>
int square(int a) //here we means the method will return an integer value
// and required an integer value to call it
{
return a*a;
}

or,

void printValue(int a) //here we means that the method will not return any
//value by using the keyword 'void' and it will just
//print the value that will be used to call the method
{
System.out.println(a+"");
}

if ur method name and class file name is same, then we say the method is a constructor. And the purpose of this method is to initial the private variable values or define the initial state of the class that will b obserbed when an object is instantied from the class.

i think it getting long.........next time, have good time, waiting for ur opinion
belal