logic problem

[Bhargav Patel]

hii..i am totally new to java when i compile this code it's run successful..but not get desired code...whts problem with it?
it's simple program to find largest among arrays..

public class JavaApp {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        int k=0;
        int i[]=new int[4];
        i[0]=12;
        i[1]=54;
        i[2]=34;
        i[3]=44;
        
        for(int j=0;j<i.length-1;j++){
        k= Math.max(i[j],i[j+1]);
          
        }
        
          System.out.println(k);
    }
}

[nir sharma]

for(int j=0;j<i.length-1;j++){
k= Math.max(i[j],i[j+1]);
} 

you need to understand what is happening in this loop.
you are only checking values at j and j+1 position in the array, and replacing the previous value of k with the new value.
you need to check whether the new value the you get from the max function is greater than the value of k or not, if not then you should not replace it.
you need to write the code on your own.

[Lexington Smith]

public class JavaApp {

    public static void main(String[] args) {
        int i[]=new int[4];
        i[0]=12;
        i[1]=54;
        i[2]=34;
        i[3]=44;
           
        int greatest = 0;        

        for(int j = 0; j < i.length - 1; j++){
        greatest = i[j]; //Let it be the greatest, until we find a bigger number in the array
        System.out.println("let the greatest be " + greatest);//To test your code, print commands are very useful
        greatest = Math.max(greatest, i[j+1]);  
        System.out.println("Greatest was found to be  " + greatest);
 
        }
        
          System.out.println("The greatest is actually " + greatest);
    }
}

Run this code and see the output.

[nir sharma]

@Lexington Smith
can you tell me what different you are doing in your code , because I am unable to find the difference and hence the same result.

[Campbell Ritchie]

Welcome to the Ranch
What did you expect to happen and what actually happened? You need to tell us that if we are to help. Also, I have added code tags, which you should always use, and you can see how much better the code looks.

[Campbell Ritchie]

Lexington Smith wrote: . . .

        for(int j = 0; j < i.length - 1; j++){
        greatest = i[j]; //Let it be the greatest, until we find a bigger number in the array
        System.out.println("let the greatest be " + greatest);//To test your code, print commands are very useful
 . . .
 

. . . .

Not convinced. I think that line you have added will produce interesting results. What do you think the output will be from {12, 54, 44, 34}?

[Swathi Kodeboyina]

@ Bhargav Patel.

The value of k is replaced every time in the loop. The value of k should be changed only if Math.max(i[j],i[j+1]) is greater than k.

for(int j=0;j<i.length-1;j++){  
        if(k < Math.max(i[j],i[j+1]))
        k= Math.max(i[j],i[j+1]);  
            
        }  

i hope this solves your problem according to what i assume your problem is. If not, tell what is the output you need?

[Lexington Smith]

Campbell Ritchie wrote:

Lexington Smith wrote: . . .

        for(int j = 0; j < i.length - 1; j++){
        greatest = i[j]; //Let it be the greatest, until we find a bigger number in the array
        System.out.println("let the greatest be " + greatest);//To test your code, print commands are very useful
 . . .
 

. . . .

Not convinced. I think that line you have added will produce interesting results. What do you think the output will be from {12, 54, 44, 34}?

Yes, I made a mistake. Corrected the code -

public class Five {

public static void main(String[] args) {
int i[]=new int[4];
i[0]=12;
i[1]=54;
i[2]=34;
i[3]=44;

int greatest = 0;
int max = 0;

for(int j = 0; j < i.length - 1; j = j+2){
max = Math.max(i[j], i[j+1]);
System.out.println("The max is " + max);
greatest = Math.max(max, greatest); //Let it be the greatest, until we find a bigger number in the array
System.out.println("let the greatest be " + greatest);//To test your code, print commands are very useful

}

System.out.println("The greatest is actually " + greatest);
}
} 

There is a bug though - if all numbers in array are negative, then your code will give 0 as the result.

[Gaurangkumar Khalasi]

Bhargav Patel wrote:...whts problem with it?

public class JavaApp {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        int k=0;
        int i[]=new int[4];
        i[0]=12;
        i[1]=54;
        i[2]=34;
        i[3]=44;

        k= Math.max(i[0],i[1]);		//Added
        for(int j=2;j<=i.length-1;j++){	//Changed Initialization and Condition	
                     k= Math.max(k,i[j]);    //Changed arguments to function 'max'      
        }
        
          System.out.println(k);
    }
}

[fred rosenberger]

Bhargav,

A couple of suggestions..

First, I would use more descriptive variable names. "k" doesn't tell me anything. however, "maxFound" tells me EXACTLY what it means...

If you want to see why your code doesn't work, put a bunch of System.out.println() statements in it to see what it is REALLY doing. something like this:

public class JavaApp {  
  
    /** 
     * @param args the command line arguments 
     */  
    public static void main(String[] args) {  
        int maxFound=0;  
        int i[]=new int[4];  
        i[0]=12;  
        i[1]=54;  
        i[2]=34;  
        i[3]=44;  
          
        for(int j=0;j<i.length-1;j++){  
           System.out.println("Comparing these values: " + i[j] + " and " + i[j+1] );
           maxFound= Math.max(i[j],i[j+1]);  
           System.out.println("Current maxFound is " + maxFound);
            
        }  
          
          System.out.println("Final result for maxFound is " + maxFound);  
    }  
}  

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