has23

how to improve an fix my above code

... again, you can read my comment here, because hard-wired reassignment of array values to new ones is fine for tiny arrays, but when dealing with larger arrays, it makes no sense to write verbatim code.

The important thing here gudii, is to know how and where you went wrong. Are you clear on that?

Your code fails because you break out of the loop at the first false result (thus returning false)

why it does that?

| should check other value also right(i am not using short cut OR like || which breaks as soon as it see first false?)

please advise

[quote][quote]public boolean has23(int[] nums) {
  int len=nums.length;
  
  for(int i=0;i<=len-1;i++)
  {
  if(nums[i]==2 | nums[i]==3)
  return true;
  
  
    if(nums[i]==3 | nums[i]==2)
  return true;
  
  else
  return false;
  }
  
  return false;
}[/quote][/quote]

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i thought above code should pass all but failed. i wonder why. please advise

return nums[0]==2||nums[0]==3||nums[1]==2||nums[1]==3;

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i like this solutiin. How to write using for loop and int i etc to take make it more universal solution similar to my approach. please advise

public boolean has23(int[] nums) {
   int len=nums.length;
  
  for(int i=0;i<=len-1;i++)
  {
    if(nums[i]==2 | nums[i]==3) return true;
  }
  return false;

}

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to take make it more universal solution similar to my approach. please advise

But the problem domain is specific and the problem is not really reusable so universality, while a good aspiration often, is probably irrelevant here

Perhaps gudii9 now wants to talk about a different problem.
Maybe one that is similar to http://codingbat.com/prob/p171022 but without the array length 2 specification.
In which case, it may be helpful if we could get a clear description of the new problem.
If we do now want to talk about a different problem perhaps it help to avoid confusion about which question is being answered if the different problem is asked in a separate question.

How my non working  below solution 


public boolean has23(int[] nums) {
  int len=nums.length;
  
  for(int i=0;i<=len-1;i++)
  {
  if(nums[i]==2 | nums[i]==3)
  return true;
  
  else
  return false;
  }
  
  return false;
}



different from working solution


public boolean has23(int[] nums) {
   int len=nums.length;
  
  for(int i=0;i<=len-1;i++)
  {
    if(nums[i]==2 | nums[i]==3) return true;
  }
  return false;

}



i see my solution has extra return false; apart from that everything looks same to me. please advise

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public boolean has23(int[] nums) {
  int len=nums.length;
  
  for(int i=0;i<=len-1;i++)
  {
  if(nums[i]==2 | nums[i]==3)
  return true;
  }
  else
  return false;
 
  
 // return false;
}

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above gives below error


Compile problems:


Error:      else
      ^^^^
Syntax error on token "else", delete this token


why i cannot write like

else
 return false;

please advise

delete this token

public boolean has23(int[] nums) {
  int len=nums.length;
  
  for(int i=0;i<=len-1;i++)
  {
  if(nums[i]==2 | nums[i]==3)
  return true;
  }
  //else
  return false;
 
  
 // return false;
}

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why i cannot write like

else is part of if...else

so i can write if without else but i cannot write a method with if and then without return after if block right?

Is my understanding is correct?


 if i write a method with if (with return ) then else(with return) and then without return at the end of the method still the compilation error is thrown by compiler right?

else is part of if...else
there is no such thing as for...else in java

public int[] front11(int[] a, int[] b) {
  int len1=a.length;
  int len2=b.length;
  
  int[] c=new int[(len1>0?1:0)+(len2>0?1:0)];
  
  if(len1>=1&len2>=1){  
  c[0]=a[0];
  c[1]=b[0];
//  return c;
  }
  
    if(len1>=1&len2==0){  
  c[0]=a[0];
  //c[1]=0;
//  return c;
  }
  
  
  
    if(len1==0&len2>=1){  
 // c[0]=0;
  c[0]=b[0];
  //return c;
  }
  
 else{
 return c;
  }
 
 //return c;
  
}

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gives error

Compile problems:


Error:      public int[] front11(int[] a, int[] b) {
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
This method must return a result of type int[]

Possible problem: the if-statement structure may theoretically
allow a run to reach the end of the method without calling return.
Consider adding a last line in the method return some_value;
so a value is always returned.

see Example Code to help with compile problems

when i write as below

public int[] front11(int[] a, int[] b) {
  int len1=a.length;
  int len2=b.length;
  
  int[] c=new int[(len1>0?1:0)+(len2>0?1:0)];
  
  if(len1>=1&len2>=1){  
  c[0]=a[0];
  c[1]=b[0];
//  return c;
  }
  
    if(len1>=1&len2==0){  
  c[0]=a[0];
  //c[1]=0;
//  return c;
  }
  
  
  
    if(len1==0&len2>=1){  
 // c[0]=0;
  c[0]=b[0];
  //return c;
  }
  
 else{
 return c;
  }
 
 return c;
  
}

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compiler is happy eventhough both else return and last return statement of method does same job in case of challenge(http://codingbat.com/prob/p128270) similar to this one

It may be better to discus this in
https://www.experts-exchange.com/questions/28691071/front11-challenge.html
but you could write as

public int[] front11(int[] a, int[] b) {
  int len1=a.length;
  int len2=b.length;
  
  int[] c=new int[(len1>0?1:0)+(len2>0?1:0)];
  
  if(len1>=1&len2>=1){  
  c[0]=a[0];
  c[1]=b[0];
//  return c;
  }
  
    if(len1>=1&len2==0){  
  c[0]=a[0];
  //c[1]=0;
//  return c;
  }
  
  
  
    if(len1==0&len2>=1){  
 // c[0]=0;
  c[0]=b[0];
  return c;
  }
  
 else{
 return c;
  }
 
// return c;
  
}

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You can do this :

public boolean thingy(){

if(true){return true;}
else return false;

}

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or this :

public static boolean thingy(){

if(true){return true;}
//else return false;
return false;

}

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but not this :

public static boolean thingy(){

if(true){return true;}
//else return false;

}

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And . . . I don't know what the others think about this, but IMHO you should ALWAYS frame if . . . else statements like this :

if( x ) { . . . ;}

else{ . . . ;}

USING curly braces EVERY TIME, even if you only use the if part.

I agree with krakatoa about the curly braces. I don't even like framing return values on the same line as the Boolean evaluation
if (true) {
return true;
} else {
return false;
}

USING curly braces EVERY TIME would be my personal preference.
I even tend to treat ){ and }else{ as two tokens, even though java treats them as five.

I don't even like framing return values on the same line as the Boolean evaluation

Yes, agreed.   Good point.    . . . and I admit to that being a bad habit of mine when I do stuff quickly, as here on EE. But it should not be in a real piece of code that way.

Ditto agreement with ozo's too.

i got it about formatting. Also i got

You can do this :

public boolean thingy(){

if(true){return true;}
else return false;




or this :

public static boolean thingy(){

if(true){return true;}
//else return false;
return false;

}



but not this :

public static boolean thingy(){

if(true){return true;}
//else return false;

}

public boolean thingy(){

if(true)

{
return true;

}
else return false;

}



above and below codes are technically same right? (even though way we write with or without else block?) please advise

public static boolean thingy(){

if(true)
{
return true;
}
//else return false;
return false;

}