當且僅當

当且仅当
dāngqiějǐndāng
if and only if

CEDICT

  1. (Mainland China, mathematics, logic) if and only if
  2. if and only if

Wiktionary

在此條件成立，並且僅在這個條件成立時

維基詞典

Examples

当且仅当你知道我们的密码你才可以进来。

You can come in if and only if you know our password.

Source: Tatoeba

当且仅当冰淇淋是香草口味，小王会吃这个冰淇淋。

If and only if the ice-cream is vanilla flavour will Xiao Wang eat it.

Source: Tatoeba

Entry Composition

1 當 dāng
  1. to be
  2. to act as
  3. manage
  4. withstand
  5. when
  6. during
  7. ought
  8. should
  9. match equally
  10. equal
  11. same
  12. obstruct
  13. just at (a time or place)
  14. on the spot
  15. right
  16. just at
2 且 qiě
  1. and
  2. moreover
  3. yet
  4. for the time being
  5. to be about to
  6. both (... and...)
3 僅 jǐn
  1. barely
  2. only
  3. merely
4 當 dāng
  1. to be
  2. to act as
  3. manage
  4. withstand
  5. when
  6. during
  7. ought
  8. should
  9. match equally
  10. equal
  11. same
  12. obstruct
  13. just at (a time or place)
  14. on the spot
  15. right
  16. just at

Related entries

若且唯若 ruòqiěwéiruò if and only if