void testMethods(){
System.out.println("Version 4. .") ;
int correct = 0 ;
int wrong = 0 ;

int[] oneTo4= {1 , 2 , 3 , 4 } ;
int sumN1 =sumEveryN(oneTo4, 2); // 

if( sumN1 == 4)
    {
    correct++;
    }
else
{
    wrong++;
    printp("sumEveryN({1 , 2 , 3 , 4 }, 2) wrong");
}

//douuble arr:
String[] str1 = {"a1","b2","c"} ;
String[] res = doubleArr(str1);
//printp(Arrays.toString(res));
if(  res[0].equals("a1") && res[1].equals("a1")  && res[2].equals("b2") && res[3].equals("b2") && res[4].equals("c") && res[5].equals("c") )
    correct++;
else
{
    wrong++;
    printp( "doubleArr({a1,b2,c}) wrong" );
}

if(indexOf5(oneTo4) == -1)
    correct++;
else
{
    wrong++;
    printp( "indexOf5({1 , 2 , 3 , 4 } ) wrong" );
}


int[] five0= {5 , 5 , 3 , 4 } ;


if(indexOf5(five0) == 0)
    correct++;
else
{
    wrong++;
    printp( " indexOf5({5 , 5 , 3 , 4 })  wrong ") ;
}


if(indexOf(five0, 5) == 0)
    correct++;
else
{
    wrong++;
    printp( " indexOf({5 , 5 , 3 , 4 }, 5)  wrong ") ;
}

if(indexOf(oneTo4, 2) == 1)
    correct++;
else
{
    wrong++;
    printp( " indexOf({1 , 2 , 3 , 4 } ,2)  wrong ") ;
}

if(indexOf(oneTo4, 999) == -1)
    correct++;
else
{
    wrong++;
    printp( " indexOf({1 , 2 , 3 , 4 }, 999 )  wrong ") ;
}



int[] x1 = {  2 , 18 , 22, 4 , 6  } ;

if(secondSmallest(x1) == 4)
    correct++;
else
{
    wrong++;
    printp("secondSmallest({  2 , 18 , 22, 4 , 6  }) wrong");
}


int[] negx1 = {  -2 , -18 , -22, -4 , -6  } ;

if(secondSmallest(negx1) == -18)
{
    correct++;
}
else
{
    wrong++;
    printp("secondSmallest({  -2 , -18 , -22, -4 , -6}) wrong");
}


int[] res2 = randos(2,20, 100) ;
int itWas = res2[0];
boolean isCorrect = true;
boolean isDiff = false;
for( int i  = 1  ; i < res2.length ; i++)
{
    int r = res2[i];
    // printp("r: " + r);
    if(r != itWas)
        isDiff= true;
    if( r < 2 || r > 20){
        isCorrect = false;
    }
    itWas = r;

}
if(isCorrect && isDiff)
    correct++;
else
{
wrong++;
printp("randos(2,20, 100) wrong, details: ") ;
printp("-----------------------") ;
if(isCorrect) 
    printp( "\t correct range of values") ;
else 
    printp( "\t wrong  range of values") ;

if(isDiff  == false) 
    printp( "\t ALl of your values are the exact same random number. Make sure that each element in the array attempts to create a ne method...") ;

printp("-----------------------") ;

}
// mean between
//
int[] arr = {1,1,2,3,4};

if (meanBetween(arr, 1,4) == 2.5){
    correct++;
}
else
{
    wrong++;
    printp("meanBetween(arr, 1,4) wrong");
}
if (meanBetween(arr, 1,4) == 2.5){
    correct++;
}
else
{
    wrong++;
    printp("meanBetween(arr, 1,4) wrong");
}

int[] arr2= {1,5,20,30,90};

if (meanBetween(arr2 , 5, 90) == 25){
    correct++;
}
else
{
    wrong++;
    printp("meanBetween( { 1,5,20,30,90} , 5, 90 ) wrong");
}



//results:
printp("\n---------------\n Results:");
printp("\t Number Correct: " + correct);
printp("\t Number wrong : " + wrong);
}


void printp(String s){
System.out.println(s);
}
void printp(int s){
System.out.println(s);
}