I generally use arrays based on their x index, and the Y placements having their items/names/ids/description/amounts.
A really simple idea would be to have 1 big array with every item in it, and you use their x index as ID reference.
example
all items
x,y
0,1 = "sword"
0,2 = swordstrength number
1,1 = "shield"
1,2 = shield strength number
2,1 = "potionX"
2.2 = potion health amount number
Then you have 1 small array, where each item you posses take up a X index, where its Y(1) hold the id from the x based index of your total inventory array, and the Y(2) determine how many you have of them.
Player Inventory
x,y
0,1 = 0 (x ID from the sword)
0,2 = 3 (you have 3 swords)
1,1 = 2 (x ID from the potion)
1,2 = 10 (you have 10 potions)
Thats the general idea.