Array.prototype.sum = function(){
	for(var i=0,sum=0;i<this.length;sum+=this[i++]);
	return sum;
}

Array.prototype.max = function(){
	return Math.max.apply({},this)
}


Array.prototype.min = function(){
	return Math.min.apply({},this)
}


Array.prototype.unique = function() {
    var a = [];
    var l = this.length;
    for(var i=0; i<l; i++) {
      for(var j=i+1; j<l; j++) {
        // If this[i] is found later in the array
        if (this[i] === this[j])
          j = ++i;
      }
      a.push(this[i]);
    }
    return a;
};

  
Array.prototype.inArray = function ( obj ) {
	var len = this.length;
	for ( var x = 0 ; x <= len ; x++ ) {
		if ( this[x] == obj ) return true;
	}
	return false;
}


Array.prototype.getPos = function ( obj ) {
	var len = this.length;
	for ( var x = 0 ; x <= len ; x++ ) {
		if ( this[x] == obj ) return x;
		
	}
	return false;
}

Array.prototype.getKeys = function(){
	
	var tmp_arr = new Array();  
	var cnt = 0;
	
    for ( key in this ){     
            tmp_arr[cnt] = key;   
            cnt++;   
        }   
 
    return tmp_arr;   
}  
   
   

//permet un VRAI reclassement numérique d'un array avec la méthode sort
//utilisation Array.sort(aSort);
function aSort(a, b){ return (a-b); }

function reduce( fn, a ){  for (i = 0; i < a.length; i++){    s = fn( s, a[i]);  }  return s;}