Swift囂鞘歌深

<貧匯准和匯准>

壓 Swift 嶄?嗤曾嶽窃侏議囂鞘?酒汽囂鞘才陣崙送囂鞘。酒汽囂鞘頁恷械需議?喘噐更夛燕器塀才蕗苧。陣崙送囂鞘夸喘噐陣崙殻會峇佩議送殻?Swift 嶄嗤眉嶽窃侏議陣崙送囂鞘?儉桟囂鞘、蛍屶囂鞘才陣崙勧弓囂鞘。

儉桟囂鞘喘噐嶷鹸峇佩旗鷹翠?蛍屶囂鞘喘噐峇佩諾怎蒙協訳周議旗鷹翠?陣崙勧弓囂鞘夸喘噐俐個旗鷹議峇佩乏會。壓不朔議偃峰嶄?繍氏峋聾仇初府耽匯嶽窃侏議陣崙送囂鞘。

頁倦繍蛍催(;)耶紗欺囂鞘議潤硫侃頁辛僉議。徽飛勣壓揖匯佩坪亟謹訳鏡羨囂鞘?萩暦駅聞喘蛍催。

GRAMMAR OF A STATEMENT
statement → expression; opt
statement → declaration; opt
statement → loop-statement; opt
statement → branch-statement; opt
statement → labeled-statement
statement → control-transfer-statement; opt
statement → statment statements; opt

儉桟囂鞘

函畳噐蒙協議儉桟訳周?儉桟囂鞘塋俯嶷鹸峇佩旗鷹翠。Swift 戻工膨嶽窃侏議儉桟囂鞘?for囂鞘、for-in囂鞘、while囂鞘才do-while囂鞘。

宥狛break囂鞘才continue囂鞘辛參個延儉桟囂鞘議陣崙送。嗤購宸曾訳囂鞘?萩歌深Break 囂鞘才Continue 囂鞘。

GRAMMAR OF A LOOP STATEMENT
loop-statement → for-statement
loop-statement → for-in-statement
loop-statement → while-statement
loop-statement → do-while-statement

For 囂鞘

for囂鞘塋俯壓嶷鹸峇佩旗鷹翠議揖扮?弓奐匯倖柴方匂。

for囂鞘議侘塀泌和?

for `initialzation`; `condition`; `increment` {
 `statements`
}

initialzation、condition才increment岻寂議蛍催?參式淫律儉桟悶statements議寄凄催脅頁音辛福待議。

for囂鞘議峇佩送殻泌和?

initialzation峪氏瓜峇佩匯肝?宥械喘噐蕗苧才兜兵晒壓俊和栖議儉桟嶄俶勣聞喘議延楚。
柴麻condition燕器塀? 泌惚葎寔(true)?statements繍氏瓜峇佩?隼朔廬欺及3化。泌惚葎邪(false)?statements才increment脅音氏瓜峇佩?for崛緩峇佩頼穎。
柴麻increment燕器塀?隼朔廬欺及2化。

協吶壓initialzation嶄議延楚叙壓for囂鞘議恬喘囃參坪嗤丼。condition燕器塀議峙議窃侏駅倬恆儉LogicValue亅咏。

GRAMMAR OF A FOR STATEMENT
for-statement → for for-init opt ; expression opt ; expression opt code-block
for-statement → for ( for-init opt ; expression opt ; expression opt ) code-block
for-statement → variable-declaration | expression-list

For-In 囂鞘

for-in囂鞘塋俯壓嶷鹸峇佩旗鷹翠議揖扮?亨旗鹿栽(賜恆儉Sequence亅咏議販吭窃侏)嶄議耽匯?。

for-in囂鞘議侘塀泌和?

for `item` in `collection` {
 `statements`
}

for-in囂鞘壓儉桟蝕兵念氏距喘collection燕器塀議generate圭隈栖資函匯倖伏撹匂窃侏?宸頁匯倖恆儉Generator亅咏議窃侏?議峙。俊和栖儉桟蝕兵?距喘collection燕器塀議next圭隈。泌惚凪卦指峙音頁None?万繍氏瓜験公item?隼朔峇佩statements?峇佩頼穎朔指欺儉桟蝕兵侃?倦夸?繍音氏験峙公item匆音氏峇佩statements?for-in崛緩峇佩頼穎。

GRAMMAR OF A FOR-IN STATEMENT
for-in-statement → for pattern in expression code-block

While 囂鞘

while囂鞘塋俯嶷鹸峇佩旗鷹翠。

while囂鞘議侘塀泌和?

while `condition` {
 `statements`
}

while囂鞘議峇佩送殻泌和?

柴麻condition燕器塀? 泌惚葎寔(true)?廬欺及2化。泌惚葎邪(false)?while崛緩峇佩頼穎。
峇佩statements?隼朔廬欺及1化。

喇噐condition議峙壓statements峇佩念祥厮柴麻竃?咀緩while囂鞘嶄議statements辛嬬氏瓜峇佩飛孤肝?匆辛嬬音氏瓜峇佩。

condition燕器塀議峙議窃侏駅倬恆儉LogicValue亅咏。揖扮?condition燕器塀匆辛參聞喘辛僉鰯協?萩歌深辛僉鰯協棋耶紗全俊。

GRAMMAR OF A WHILE STATEMENT
while-statement → while while-condition code-block
while-condition → expression | declaration

Do-While 囂鞘

do-while囂鞘塋俯旗鷹翠瓜峇佩匯肝賜謹肝。

do-while囂鞘議侘塀泌和?

do {
 `statements`
} while `condition`

do-while囂鞘議峇佩送殻泌和?

峇佩statements?隼朔廬欺及2化。
柴麻condition燕器塀? 泌惚葎寔(true)?廬欺及1化。泌惚葎邪(false)?do-while崛緩峇佩頼穎。

喇噐condition燕器塀議峙頁壓statements燕器塀峇佩朔嘉柴麻竃?咀緩do-while囂鞘嶄議statements崛富氏瓜峇佩匯肝。

condition燕器塀議峙議窃侏駅倬恆儉LogicValue亅咏。揖扮?condition燕器塀匆辛參聞喘辛僉鰯協?萩歌深辛僉鰯協棋耶紗全俊。

GRAMMAR OF A DO-WHILE STATEMENT
do-while-statement → do code-block while while-condition

蛍屶囂鞘

函畳噐匯倖賜宀謹倖訳周議峙?蛍屶囂鞘塋俯殻會峇佩峺協何蛍議旗鷹。?堡撮iii嶽в鐓籌侈?骶綴欺?畩檞28膾侶嶽б埃慰莞伉漬賛藉翮襦?Swift 戻工曾嶽窃侏議蛍屶囂鞘?if囂鞘才switch囂鞘。

switch囂鞘嶄議陣崙送辛參喘break囂鞘俐個?萩歌深Break 囂鞘。

GRAMMAR OF A BRANCH STATEMENT
branch-statement → if-statement
branch-statement → switch-statement

If 囂鞘

函畳噐匯倖賜謹倖訳周議峙?if囂鞘繍畳協峇佩陳匯翠旗鷹。

if囂鞘嗤曾嶽炎彈侘塀?壓宸曾嶽侘塀戦脅駅倬嗤寄凄催。

及匯嶽侘塀頁輝拝叙輝訳周葎寔扮峇佩旗鷹?崧和中宸劔?

if `condition` {
 `statements`
}

及屈嶽侘塀頁壓及匯嶽侘塀議児粥貧耶紗else囂鞘?輝峪嗤匯倖else囂鞘扮?崧和中宸劔?

if `condition` {
 `statements to execute if condition is true`
} else {
 `statements to execute if condition is false`
}

揖扮?else囂鞘匆辛淫根if囂鞘?貫遇侘撹匯訳全栖霞編厚謹議訳周?崧和中宸劔?

if `condition 1` {
 `statements to execute if condition 1 is true`
} else if `condition 2` {
 `statements to execute if condition 2 is true`
}
else {
 `statements to execute if both conditions are false`
}

if囂鞘嶄訳周議峙議窃侏駅倬恆儉LogicValue亅咏。揖扮?訳周匆辛參聞喘辛僉鰯協?萩歌深辛僉鰯協棋耶紗全俊。

GRAMMAR OF AN IF STATEMENT
if-statement → if if-condition code-block else-clause opt
if-condition → expression | declaration
else-clause → else code-block | else if-statement opt

Switch 囂鞘

函畳噐switch囂鞘議陣崙燕器塀(control expression)?switch囂鞘繍畳協峇佩陳匯翠旗鷹。

switch囂鞘議侘塀泌和?

switch `control expression` {
 case `pattern 1`:
 `statements`
 case `pattern 2` where `condition`:
 `statements`
 case `pattern 3` where `condition`,
 `pattern 4` where `condition`:
 `statements`
 default:
 `statements`
}

switch囂鞘議陣崙燕器塀(control expression)氏遍枠瓜柴麻?隼朔嚥耽匯倖case議庁塀(pattern)序佩謄塘。泌惚謄塘撹孔?殻會繍氏峇佩斤哘議case翠戦議statements。総翌?耽匯倖case翠脅音嬬葎腎?匆祥頁傍壓耽匯倖case翠嶄崛富嗤匯訳囂鞘。泌惚低音?壓謄塘欺議case翠嶄峇佩旗鷹?峪俶壓翠戦亟匯訳break囂鞘軸辛。

辛參喘恬陣崙燕器塀議峙頁噴蛍痩試議?茅阻炎楚窃侏(scalar types?泌Int、Character)翌?低辛參聞喘販採窃侏議峙?淫凄検泣方、忖憲堪、圷怏、徭協吶窃議糞箭才辛僉(optional)窃侏?封崛頁旦訟窃侏嶄議撹埀峙才峺協議袈律(range)吉。購噐壓switch囂鞘嶄聞喘宸乂窃侏?萩歌深陣崙送匯嫗議Switch。

低辛參壓庁塀朔中耶紗匯倖軟隠擦恬喘議燕器塀(guard expression)。軟隠擦恬喘議燕器塀頁宸劔更撹議?購囚忖where朔中効彭匯倖恬葎駆翌霞編訳周議燕器塀。咀緩?輝拝叙輝陣崙燕器塀謄塘匯倖case議蝶倖庁塀拝軟隠擦恬喘議燕器塀葎寔扮?斤哘case翠嶄議statements嘉氏瓜峇佩。壓和中議箭徨嶄?陣崙燕器塀峪氏謄塘根曾倖屢吉圷殆議圷怏?泌(1, 1)?

case let (x, y) where x == y:

屎泌貧中宸倖箭徨?匆辛參壓庁塀嶄聞喘let?賜var?囂鞘栖鰯協械楚?賜延楚?。宸乂械楚?賜延楚?辛參壓凪斤哘議軟隠擦恬喘議燕器塀才凪斤哘議case翠戦議旗鷹嶄哈喘。徽頁?泌惚case嶄嗤謹倖庁塀謄塘陣崙燕器塀?椎担宸乂庁塀脅音嬬鰯協械楚?賜延楚?。

switch囂鞘匆辛參淫根潮範(default)翠?峪嗤凪万case翠脅涙隈謄塘陣崙燕器塀扮?潮範翠嶄議旗鷹嘉氏瓜峇佩。匯倖switch囂鞘峪嬬嗤匯倖潮範翠?遇拝駅倬壓switch囂鞘議恷朔中。

勝砿庁塀謄塘荷恬糞縞議峇佩乏會?蒙艶頁庁塀議柴麻乏會頁音辛岑議?徽頁 Swift 号協switch囂鞘嶄議庁塀謄塘議乏會才慕亟坿旗鷹議乏會隠隔匯崑。咀緩?輝謹倖庁塀根嗤屢揖議峙拝嬬校謄塘陣崙燕器塀扮?殻會峪氏峇佩坿旗鷹嶄及匯倖謄塘議case翠嶄議旗鷹。

Switch 囂鞘駅倬頁頼姥議

壓 Swift 嶄?switch囂鞘嶄陣崙燕器塀議耽匯倖辛嬬議峙脅駅倬崛富嗤匯倖case翠嚥岻斤哘。壓蝶乂秤趨和?箭泌?燕器塀議窃侏頁Int??低辛參聞喘潮範翠諾怎乎勣箔。

音贋壓咨塀議香刊(fall through)

輝謄塘議case翠嶄議旗鷹峇佩頼穎朔?殻會氏嶮峭switch囂鞘?遇音氏写偬峇佩和匯倖case翠。宸祥吭龍彭?泌惚低?峇佩和匯倖case翠?俶勣?塋週慥敖穉菻ź?case翠戦聞喘fallthrough囂鞘。購噐fallthrough囂鞘議厚謹佚連?萩歌深Fallthrough 囂鞘。

GRAMMAR OF A SWITCH STATEMENT
switch-statement → switch expression { switch-cases opt }
switch-cases → switch-case switch-cases opt
switch-case → case-label statement | default-label statements
switch-case → case-label ; | default-label ;
case-label → case case-item-list :
case-item-list → pattern guard-clause opt | pattern guard-clause opt, case-item-list
default-label → default :
guard-clause → where guard-expression
guard-expression → expression

揮炎禰議囂鞘
低辛參壓儉桟囂鞘賜switch囂鞘念中紗貧炎禰?万喇炎禰兆才諸昧凪朔議丹催(:)怏撹。壓break才continue朔中効貧炎禰兆辛參?塋週慥斫VII罫鐓篁?switch囂鞘嶄厚個陣崙送?委陣崙幡勧弓公峺協炎禰炎芝議囂鞘。購噐宸曾訳囂鞘喘隈?萩歌深Break 囂鞘才Continue 囂鞘。

炎禰議恬喘囃頁乎炎禰侭炎芝議囂鞘岻朔議侭嗤囂鞘。低辛參音聞喘揮炎禰議囂鞘?徽峪勣聞喘万?炎禰兆祥駅率匯。

購噐聞喘揮炎禰議囂鞘議箭徨?萩歌深陣崙送匯嫗議揮炎禰議囂鞘棋耶紗全俊。

GRAMMAR OF A LABELED STATEMENT
labeled-statement → statement-label loop-statement | statement-label switch-statement
statement-label → label-name :
label-name → identifier

陣崙勧弓囂鞘

宥狛涙訳周仇委陣崙幡貫匯頭旗鷹勧弓欺総匯頭旗鷹?陣崙勧弓囂鞘嬬校個延旗鷹峇佩議乏會。Swift 戻工膨嶽窃侏議陣崙勧弓囂鞘?break囂鞘、continue囂鞘、fallthrough囂鞘才return囂鞘。

GRAMMAR OF A CONTROL TRANSER STATEMENT
control-transfer-statement → break-statement
control-transfer-statement → continue-statement
control-transfer-statement → fallthrough-statement
control-transfer-statement → return-statement

Break 囂鞘

break囂鞘喘噐嶮峭儉桟賜switch囂鞘議峇佩。聞喘break囂鞘扮?辛參峪亟break宸倖購囚簡?匆辛參壓break朔中効貧炎禰兆(label name)?崧和中宸劔?

break
break `label name`

輝break囂鞘朔中揮炎禰兆扮?辛喘噐嶮峭喇宸倖炎禰炎芝議儉桟賜switch囂鞘議峇佩。

遇輝峪亟break扮?夸氏嶮峭switch囂鞘賜貧和猟嶄淫根break囂鞘議恷坪蚊儉桟議峇佩。

壓宸曾嶽秤趨和?陣崙幡脅氏瓜勧弓公儉桟賜switch囂鞘翌中議及匯佩囂鞘。

購噐聞喘break囂鞘議箭徨?萩歌深陣崙送匯嫗議Break棋耶紗全俊才揮炎禰議囂鞘棋耶紗全俊。

GRAMMAR OF A BREAK STATEMENT
break-statement → break label-name opt

Continue 囂鞘

continue囂鞘喘噐嶮峭儉桟嶄輝念亨旗議峇佩?徽音氏嶮峭乎儉桟議峇佩。聞喘continue囂鞘扮?辛參峪亟continue宸倖購囚簡?匆辛參壓continue朔中効貧炎禰兆(label name)?崧和中宸劔?

continue
continue `label name`

輝continue囂鞘朔中揮炎禰兆扮?辛喘噐嶮峭喇宸倖炎禰炎芝議儉桟嶄輝念亨旗議峇佩。

遇輝峪亟break扮?辛喘噐嶮峭貧和猟嶄淫根continue囂鞘議恷坪蚊儉桟嶄輝念亨旗議峇佩。

壓宸曾嶽秤趨和?陣崙幡脅氏瓜勧弓公儉桟翌中議及匯佩囂鞘。

壓for囂鞘嶄?continue囂鞘峇佩朔?increment燕器塀珊頁氏瓜柴麻?宸頁咀葎耽肝儉桟悶峇佩頼穎朔increment燕器塀脅氏瓜柴麻。

購噐聞喘continue囂鞘議箭徨?萩歌深陣崙送匯嫗議Continue棋耶紗全俊才揮炎禰議囂鞘棋耶紗全俊。

GRAMMAR OF A CONTINUE STATEMENT
continue-statement → continue label-name opt

Fallthrough 囂鞘

fallthrough囂鞘喘噐壓switch囂鞘嶄勧弓陣崙幡。fallthrough囂鞘氏委陣崙幡貫switch囂鞘嶄議匯倖case勧弓公和匯倖case。宸嶽勧弓頁涙訳周議?軸聞和匯倖case議峙嚥switch囂鞘議陣崙燕器塀議峙音謄塘。

fallthrough囂鞘辛竃孖壓switch囂鞘嶄議販吭case戦?徽音嬬竃孖壓恷朔匯倖case翠嶄。揖扮?fallthrough囂鞘匆音嬬委陣崙幡勧弓公聞喘阻辛僉鰯協議case翠。

購噐壓switch囂鞘嶄聞喘fallthrough囂鞘議箭徨?萩歌深陣崙送匯嫗議陣崙勧弓囂鞘棋耶紗全俊。

GRAMMAR OF A FALLTHROUGH STATEMENT
continue-statement → fallthrough

Return 囂鞘

return囂鞘喘噐壓痕方賜圭隈議糞孖嶄繍陣崙幡勧弓公距喘宀?俊彭殻會繍氏貫距喘宀議了崔写偬?和峇佩。

聞喘return囂鞘扮?辛參峪亟return宸倖購囚簡?匆辛參壓return朔中効貧燕器塀?崧和中宸劔?

return
return `expression`

輝return囂鞘朔中揮燕器塀扮?燕器塀議峙繍氏卦指公距喘宀。泌惚燕器塀峙議窃侏嚥距喘宀豚李議窃侏音謄塘?Swift 夸氏壓卦指燕器塀議峙岻念繍燕器塀峙議窃侏廬算葎距喘宀豚李議窃侏。

遇輝峪亟return扮?叙叙頁繍陣崙幡貫乎痕方賜圭隈勧弓公距喘宀?遇音卦指匯倖峙。?宸祥頁傍?乎痕方賜圭隈議卦指窃侏葎Void賜()?

GRAMMAR OF A RETURN STATEMENT
return-statement → return expression opt