problem with output in array

[mike longs]

i need to output the index for the lowest value and now all i am able to output is [0][1] im not sure why

 class Arrayed
 {
 public static void main( String [] args )
 {
 double [] [] temp = { { 43, 3},
 { 50, 6 },
 { 66, 32},
 { 68, 40},
 { 75, 55},
 { 88, 50},
 { 90, 66},
 { 98, 65},
 { 85, 50},
 { 76, 43},
 { 65, 42},
 { 52, 15} };
 
String [] string = { "high", "low", };
 for( int i = 0; i < string.length; i++ )
 System.out.println( " string " + i + " : "
 +string[i] );
 
Scanner scan = new Scanner( System.in );
 int currentLow;
 do
 {
 System.out.print( "Enter 1 for low > " );
 currentLow = scan.nextInt( );
 } while ( currentLow < 0 || currentLow > 1 );

 double indexLowTemp = temp[0][currentLow]; 
for ( int i = 1; i > temp.length; i++ ) { if ( currentLow < temp[i].length ) 
{ 
if ( temp[i][currentLow] > indexLowTemp ) 
indexLowTemp = temp[i][currentLow]; 
} 
} 
System.out.println ( "\nThe min temp for " + string[currentLow] + " is " +( indexLowTemp ) );

 }
 }

[Mansukhdeep Thind]

Welcome to the ranch Mike. Always use code tags while referring to Java code:

package test;

import java.util.Scanner;

public class Arrayed
{
	public static void main( String [] args )
	{
		double [] [] temp = { { 43, 3},
				{ 50, 6 },
				{ 66, 32},
				{ 68, 40},
				{ 75, 55},
				{ 88, 50},
				{ 90, 66},
				{ 98, 65},
				{ 85, 50},
				{ 76, 43},
				{ 65, 42},
				{ 52, 15} };

		String [] string = { "high", "low", };
		for( int i = 0; i < string.length; i++ )
			System.out.println( " string " + i + " : "
					+string[i] );

		Scanner scan = new Scanner( System.in );
		int currentLow;
		do
		{
			System.out.print( "Enter 1 for low > " );
			currentLow = scan.nextInt( );
		} while ( currentLow < 0 || currentLow > 1 );

		double indexLowTemp = temp[0][currentLow];
		for ( int i = 1; i > temp.length; i++ ) { if ( currentLow < temp[i].length )
		{
			if ( temp[i][currentLow] > indexLowTemp )
				indexLowTemp = temp[i][currentLow];
		}
		}
		System.out.println ( "\nThe min temp for " + string[currentLow] + " is " +( indexLowTemp ) );

	}
} 

Much more readable now.

[Jeff Verdegan]

Hi, and welcome to the Ranch!

In the future, please UseCodeTags(←click) when posting code so it will retain formatting and be readable. I added them for you here, and that helped a little, but your indentation is a bit wonky. Please google for and follow Sun's (Oracle's) Java coding conventions.

Look at this bit:

for ( int i = 1; i > temp.length; i++ )

That says:
1. Initialize i to 1.
2. As long as i is larger than tmp.length, do the following:
2.1 execute the loop body
2.2 increment i
2.3 go back to 2.

Do you see the problem there?

[Mansukhdeep Thind]

Jeff
I am not able to understand what is the logic that Mike is using to find the smallest element in the array of array of double primitives. Can you explain?

[mike longs]

would it be the fact that i am looking if i is larger than temp.length when it should be looking for if i is larger than one of indexs in the array ?

[Joanne Neal]

mikey mike wrote:would it be the fact that i am looking if i is larger than temp.length when it should be looking for if i is larger than one of indexs in the array ?

No.
Your for loop will only execute if the condition (i > temp.length) is true.
What's the initial value of i. Is that greater than temp.length ?

[Campbell Ritchie]

No.

[mike longs]

well i is set to 1, and temp is an array so im not exactly sure what temp.length would even be besides and array thats 11 rows and 1 column( if you count 0 )

[fred rosenberger]

note that java does not have multi-dimensional arrays. It only has 1-d arrays, but an array can hold...other arrays.

So, your temp array is really an array that holds arrays of doubles. temp holds 12 arrays, so it has a length of 12.

So, the first time you get to your loop, i is 1, and temp.length is 12. So...how many times will your loop run?

[mike longs]

it would only run one time... thats why i was only getting the number in the first index

double indexLowTemp = temp[0][currentLow]; 
	for ( int i = 1; i < temp.length; i++ ) { if ( currentLow < temp[i].length ) 
	{ 
	 if ( temp[i][currentLow] < indexLowTemp ) 
	 indexLowTemp = temp[i][currentLow];

and that is able to output any number that is the lowest... but i am still having trouble getting the index to output instead of the actual value

[fred rosenberger]

mikey mike wrote:it would only run one time... thats why i was only getting the number in the first index

actually, it shouldn't run at all.

for ( int i = 1; i > temp.length; i++ ) 

The firs time you come to this line of code, i is set to 1. temp.length is 12. so, the very first time you hit this line, the condition is false, so you drop out of this for loop entirely - no line of code in the body was ever executed.

[mike longs]

yea your right but with my updated code

double indexLowTemp = temp[0][currentLow];    
    for ( int i = 1; i < temp.length; i++ ) { if ( currentLow < temp[i].length )    
    {    
     if ( temp[i][currentLow] < indexLowTemp )    
     indexLowTemp = temp[i][currentLow];  

it works fine im just having a problem outputting the index instead of the actual value, i can do this on a one dime array but the 2 dime seems to throw me off

[fred rosenberger]

what do you mean by " the index instead of the actual value". The index of what?

[mike longs]

ok so for the lowest temp in the array is 3 and i keep only outputting the "3" but i am supposed to return the "index of the lowest temp in the array" so it seems to me it would be at [0][1]. or say that it was the six instead of the "3" it would be [1][1]. and im not sure when the index would output what kind of format it would return in

[mike longs]

ok so im pretty sure i figured it out for the min. now i am working on the max and ihave this

import java.util.Scanner;

public class Arrayhigh
{
	public static void main( String [] args )
	{
	double [] [] temp =	 { { 43, 3},
									{ 50, 6 },
									{ 66, 32},
									{ 68, 40},
									{ 75, 55},
									{ 98, 50},
									{ 90, 66},
									{ 92, 65},
									{ 85, 50},
									{ 76, 43},
									{ 65, 42},
									{ 52, 15} };

	String [] string = { "high", "low", };
			for( int i = 0; i < string.length; i++ )
			System.out.println( " string " + i + " : "
										+string[i] );


									
									
Scanner scan1 = new Scanner( System.in );
		int currentHigh;
		do
		{
			System.out.print( "Enter 0 for high > " );
			currentHigh = scan1.nextInt( );
		}	while ( currentHigh < 0 || currentHigh > 1 );
		
		double indexHighTemp = temp[currentHigh][0];
		for ( int i = 1; i < temp.length; i++ )
		{
			if ( currentHigh < temp[i].length )
			{
			
				if (temp[i][currentHigh] > indexHighTemp )
					
					indexHighTemp = temp[i][currentHigh];
			}
			
		}
				System.out.println ( "\nThe max temp for "
									+ string[currentHigh] + " is "
									+( indexHighTemp ) );
}
}

i can get it to output the 98 as the max, but if i change indexHighTemp = i , it outputs an 11 instead of a 5. im not sure why my loop is running that many times
and both of these min and max are supposed to be set in one program with indexHighTemp and indexLowTemp as 2 seperate methods and i am having a problem setting the methods

[Mack Wilmot]

It would help if you named your variables for what they really are. indexHighTemp is a double and being used for a temperature and not an index in your code. It should be called highTemp.