test for items in player inventory

/testfor @p {SelectedItemSlot:0}

testfor @p[r=10] {Inventory:[{id:"minecraft:diamond_sword"}]}

testfor @p[r=10] {Inventory:[{Slot:0b,id:"minecraft:diamond_sword"}]}

testfor @p[r=10] {SelectedItemSlot:0,Inventory:[{Slot:0b,id:"minecraft:diamond_sword"}]}

testfor @p[r=10] {Inventory:[{tag:{display:{Name:"Ice Blade"}}}]}

testfor @p[r=10] {SelectedItemSlot:0,Inventory:[{Slot:0b,tag:{display:{Name:"Ice Blade"}}}]}