How to count string values, how many times are they repeated?

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I have a list of symbols. 

Pairs = "EURUSD,GBPUSD,GBPUSD,USDCHF,USDJPY";


I want to know how many times "USD" is repeated in this list.

Pairs = "EURUSD,GBPUSD,GBPUSD,USDCHF,USDJPY";

I want to know this for others as well, for example for "GBP" and "EUR".

 
Milan Zivanovic: I want to know how many times "USD" is repeated in this list.
So go through the list and count them. What's the problem?
 
William Roeder #:
So go through the list and count them. What's the problem?

I don't know why, always gives me back 1.


int ArrayValCnt(string& array[], string val)
{  
   int cnt = 0;
   for(int z=0;z<ArraySize(array);z++)
   {
      if(StringFind(array[z],val)>-1)  
      cnt++;
   }
   return(cnt);
}
 
Milan Zivanovic #:

I don't know why, always gives me back 1.


How are you calling ArrayValCnt? What values are you passing to it? Because in the first post,
the list you posted is not an array.

 
Alexandre Borela #:

How are you calling ArrayValCnt? What values are you passing to it? Because in the first post,
the list you posted is not an array.

maybe I wasn’t clear enough at first post. I wanted to make it as simple as possible. It can be array or list, I tried both.








int ArrayValCnt(string& array[], string val)
{  
   int cnt = 0;
   for(int z=0;z<ArraySize(array);z++)
   {
      if(StringFind(array[z],val)>-1)  
      cnt++;
   }
   return(cnt);
}





Pairs = "EURUSD,GBPUSD,GBPUSD,USDCHF,USDJPY";
StringSplit(Pairs,',',TradePairs);
for(int i=0; i<ArraySize(TradePairs); i++)
   { 
        ArrayValCnt(TradePairs[i], "USD");
   }
 
Milan Zivanovic #:

maybe I wasn’t clear enough at first post. I wanted to make it as simple as possible. It can be array or list, I tried both.


I see the error. You first split string which means your ArrayValCnt only see only 1 element. Call it directly on the split string:

Pairs = "EURUSD,GBPUSD,GBPUSD,USDCHF,USDJPY";
StringSplit(Pairs,',',TradePairs);
int usdCount = ArrayValCnt(TradePairs, "USD");
 
Alexandre Borela #:
I see the error. You first split string which means your ArrayValCnt only see only 1 element. Call it directly on the split string:

This can work, thanks for the help.

  
//+------------------------------------------------------------------+
//| StringCountMatches.                                              |
//+------------------------------------------------------------------+
/**
* Counts the number of all occurrences of the specified string in
* the input string using case-sensitive search.
* Example:
*      string str = "Mr Blue has a blue house and a blue car";
*      Print( StringCountMatches(str, "blue") );  // 2
*/
int StringCountMatches(string sourceStr, string searchStr)
  {
   int count = StringReplace(sourceStr, searchStr, "");;
   return count;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void OnStart()
  {
   string Pairs = "EURUSD,GBPUSD,GBPUSD,USDCHF,USDJPY";
   int count = StringCountMatches(Pairs, "USD");
   Print("Count of matches: ", count);

  }
//+------------------------------------------------------------------+

// Count of matches: 5


String Manipulation Functions - library

https://www.mql5.com/en/code/35395

String Manipulation Functions
String Manipulation Functions
  • www.mql5.com
A collection of useful string manipulation functions.
 
amrali #:


String Manipulation Functions - library

https://www.mql5.com/en/code/35395

This solution is far worse than the one OP posted with StringFind as you will generate unnecessary temporary strings.

  
//+------------------------------------------------------------------+
//| StringCountMatches.                                              |
//+------------------------------------------------------------------+
/**
* Counts the number of all occurrences of the specified string in
* the input string using case-sensitive search.
* Example:
*      string str = "Mr Blue has a blue house and a blue car";
*      Print( StringCountMatches(str, "blue") );  // 2
*/
int StringCountMatches(string sourceStr, string searchStr)
  {
// return StringReplace(sourceStr, searchStr, "");
   int count = 0;
   int pos = 0;
   while((pos = StringFind(sourceStr, searchStr, pos)) != -1)
     {
      count++;
      pos += StringLen(searchStr);
     }
   return count;
  }
 
Alexandre Borela #:

This solution is far worse than the one OP posted with StringFind as you will generate unnecessary temporary strings.

It works, coz I don't bother micro-optimizations..

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