javascriptの参照と値

javascriptの参照渡しと値渡しについて

Transcript

1. JAVASCRIPT REFERENCES & VALUES
2. Name @brn (⻘野健利) Occupation フロントエンドエンジニア・ネイティブエンジニア Company Cyberagent アドテクスタジオ AI Messenger OSS Contributor of V8 About http://info.b6n.ch
3. References and Values ࢀর ஋
4. References and Values ஋ ஋ ࢀর ࢀর
5. References and Values ࢀর͸ؒ઀తʹΦϒδΣΫτΛมߋ͢Δ
   ஋͸௚઀ͦͷΦϒδΣΫτΛมߋ͢Δ
6. References or Values? KBWBTDSJQU͸ࢀরͱ஋ͷ྆ํΛ࢖͏
   ΦϒδΣΫτຖʹͲ͏ѻΘΕΔ͔ܾ·͍ͬͯΔ
7. Javascript object traits ࢀর
   "MM
   WBMVFT
   FYUFOET
   0CKFDU
   ஋
   TUSJOH
   OVNCFS
   CPPMFBO
8. Pass by reference/value const A = const B = ࢀর ஋ A = B = ஋
9. Pass by reference const A = {}; const B = A; B.x = 1; console.log(A); // { x: 1 }
10. Pass by value const A = 1; const B = A; B++; console.log(A); // 1
11. Until here… ͱɺ͜͜·Ͱ͕Α͘ݴΘΕ͍ͯΔ
    ࠓճ͸΋͏ͪΐ͍ਂ۷Γͯ͠Έ͍ͨ
12. Mutable, Immutable KBWBTDSJQUʹ͸
    มߋՄೳͳ஋ͱมߋෆՄೳͳ஋͕͋Δ
    TUSJOH
    OVNCFS
    CPPMFBO͸มߋͰ͖ͳ͍
13. Special cases OVNCFSͱCPPMFBO͸஋౉͠Ͱ͋Δ͜ͱ͕ଟ͍
    ͨͩ͠TUSJOH͸৭ʑͳ޻෉͕͋Δέʔε͕ଟ͍
    7Ͱ͸TUSJOH͸ࢀরͱͳ͍ͬͯΔ
14. String behave like value let A = 'a'; let B = A; A += 'b' // Create new instance and assign to self. console.log(A); // 'ab'; console.log(B); // 'a;
15. Immutablity make reference to value *NNVUBCMFͳจࣈྻ͕஋ͷΑ͏ʹৼΔ෣͏͕
    ࣮ࡍʹ͸͢΂ͯࢀরΛ౉͍ͯ͠Δ
16. What is reference? ࢀরͱ͸ͳΜͩΖ͏
17. Pointer ΦϒδΣΫτ͸ੜ੒͞ΕΔͱώʔϓྖҬͱ͍͏ϝ ϞϦʹׂΓ౰ͯΒΕΔ
    ͦͷΦϒδΣΫτΛૢ࡞͢Δ৔߹͸ͦͷϝϞϦྖ ҬΛࢦࣔ͢͠ΞυϨεΛඞཁͱ͢Δ
    ͜Ε͕ϙΠϯλͱݺ͹ΕΔ΋ͷ
18. Pointer is value KTΤϯδϯΛ࣮૷͍ͯ͠Δ$$ ͷੈքͰ͸
    ϙΠϯλͦͷ΋ͷ΋·ͨ஋Ͱ͋Δ
    ͦͷͨΊϙΠϯλͷϙΠϯλΛ࡞ͬͨΓ΋Ͱ͖Δ
19. Reference is value ͔͠͠KBWBTDSJQUͷੈքͰ͸ࢀরͷࢀর͸࡞Εͳ͍
    ͭ·Γࢀর͸ৗʹ஋౉͠ͱͳΔ
20. pass by copy reference ͭ·ΓKBWBTDSJQUͰ͸
    ࢀর ϙΠϯλ Λ஋౉͍ͯ͠͠Δ
    ࢀরͷ஋౉͠
    ͱͳ͍ͬͯΔ
21. Appendix 7಺෦ͷจࣈྻ࣮૷Λ؆୯ʹ
22. String in V8 7Ͱ͸จࣈྻ͕ҎԼͷΫϥεʹ෼͔Ε͍ͯΔ
    4FR0OF#ZUF4USJOH
    4FR5XP#ZUF4USJOH
    $POT4USJOH
    5IJO4USJOH
    4MJDFE4USJOH
23. String in V8 ಛʹTVCTUSJOHΛߦͬͨΓͯ͠
    ৽ͨʹจࣈྻΠϯελϯεΛ࡞੒͢Δ৔߹
    3PQFͱ͍͏ΞϧΰϦζϜΛར༻ͨ͠
    $POT4USJOH͕ར༻͞ΕΔ
24. Rope จࣈྻͷ݁߹͕ߴ଎0 MPH
    O
    ෼ׂ΋ߴ଎0 MPH
    O
    औΓग़͠0 MPH
    O
25. Rope 5PEBZ
    JT
    XF
    BSF
    KBWBTDSJQUFS`T 5PEBZ
    JT XF
    BSF
    KBWBTDSJQUFS`T 3005
26. Rope 5PEBZ
    JT 3005 8F
    BSF KBWBTDSJQUFS`T 53&&
27. Summary ࢀরͱ஋͔Β3PQF·ͰோΊͯΈ·ͨ͠
    ͝ਗ਼ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠