docs: public static int count(String str,String target){
  		int count=0; 
  		int index=0; 
  		while(true){ 
  			index=str.indexOf(target,index+1); 
  			if(index>0){ 
  				count++; 
  			}else{ 
  				break; 
  			} 
  		} 
  		return count; 
  	}