Swift中的74个内建函数

 
 
 
  
abs(...)
 
 
  
advance(...)
 
 
  
alignof(...)
 
 
  
alignofValue(...)
 
 
  
assert(...)
 
 
  
bridgeFromObjectiveC(...)
 
 
  
bridgeFromObjectiveCUnconditional(...)
 
 
  
bridgetoObjectiveC(...)
 
 
  
bridgetoObjectiveCUnconditional(...)
 
 
  
c_malloc_size(...)
 
 
  
c_memcpy(...)
 
 
  
c_putchar(...)
 
 
  
contains(...)
 
 
  
count(...)
 
 
  
countElements(...)
 
 
  
countLeadingZeros(...)
 
 
  
debugPrint(...)
 
 
  
debugPrintln(...)
 
 
  
distance(...)
 
 
  
dropFirst(...)
 
 
  
dropLast(...)
 
 
  
dump(...)
 
 
  
encodeBitsAsWords(...)
 
 
  
enumerate(...)
 
 
  
equal(...)
 
 
  
filter(...)
 
 
  
find(...)
 
 
  
getBridgedobjectiveCType(...)
 
 
  
getVaList(...)
 
 
  
indices(...)
 
 
  
insertionSort(...)
 
 
  
isBridgedToObjectiveC(...)
 
 
  
isBridgedVerbatimToObjectiveC(...)
 
 
  
isUniquelyReferenced(...)
 
 
  
join(...)
 
 
  
lexicographicalCompare(...)
 
 
  
map(...)
 
 
  
max(...)
 
 
  
maxElement(...)
 
 
  
min(...)
 
 
  
minelement(...)
 
 
  
numericCast(...)
 
 
  
partition(...)
 
 
  
posix_read(...)
 
 
  
posix_write(...)
 
 
  
print(...)
 
 
  
println(...)
 
 
  
quickSort(...)
 
 
  
reduce(...)
 
 
  
reflect(...)
 
 
  
reinterpretCast(...)
 
 
  
reverse(...)
 
 
  
roundUpToAlignment(...)
 
 
  
sizeof(...)
 
 
  
sizeofValue(...)
 
 
  
sort(...)
 
 
  
split(...)
 
 
  
startsWith(...)
 
 
  
strideof(...)
 
 
  
strideofValue(...)
 
 
  
swap(...)
 
 
  
swift_MagicMirrorData_summaryImpl(...)
 
 
  
swift_bufferAllocate(...)
 
 
  
swift_keepAlive(...)
 
 
  
toString(...)
 
 
  
transcode(...)
 
 
  
underestimateCount(...)
 
 
  
unsafeReflect(...)
 
 
  
withExtendedLifetime(...)
 
 
  
withObjectAtPlusZero(...)
 
 
  
withUnsafePointer(...)
 
 
  
withUnsafePointerToObject(...)
 
 
  
withUnsafePointers(...)
 
 
  
withVaList(...) 
 

 

一些常用的：

abs(signednumber): 返回给定的有符号数字的绝对值。很简单，但是没有在文档中记录。

abs(-1)==1abs(-42)==42abs(42)==42

contains(sequence,element): 如果给定的序列（如数组）包含特定的元素，则返回true。

varlanguages=["Swift","Objective-C"]contains(languages,"Swift")==truecontains(languages,"Java")==falsecontains([29,85,42,96,75],42)==true

dropFirst(sequence): 返回一个去掉第一个元素的新序列（如数组）。

varlanguages=["Swift","Objective-C"]varoldLanguages=dropFirst(languages)equal(oldLanguages,["Objective-C"])==true

dropLast(sequence): 返回一个的新序列（如数组），该序列去掉作为参数传递给函数的最后一个元素。

varlanguages=["Swift","Objective-C"]varnewLanguages=dropLast(languages)equal(newLanguages,["Swift"])==true

dump(object): 一个对象的内容转储到标准输出。

varlanguages=["Swift","Objective-C"]dump(languages)//Prints://?2elements//-[0]:Swift//-[1]:Objective-C

equal(sequence1,sequence2): 如果序列1和序列2包含相同的元素，则返回true。

varlanguages=["Swift","Objective-C"]equal(languages,["Swift","Objective-C"])==truevaroldLanguages=dropFirst(languages)equal(oldLanguages,["Objective-C"])==true

filter(sequence,includeElementClosure): 返回序列的一个元素，这个元素满足includeElementClosure所指定的条件。

foriinfilter(1...100,{$0%10==0}){//10,20,30,...println(i)assert(contains([10,40,50,60,70,80,90,100],i))}

find(sequence,element): 再给定的序列中返回一个指定的索引，如果在序列中没有找到这个元素就返回nil。

varlanguages=["Swift","Objective-C"]find(languages,"Objective-C")==1find(languages,"Java")==nilfind([29,42)==2

indices(sequence): 在指定的序列中返回元素的索引（零索引）。

equal(indices([29,42]),[0,1,2])foriinindices([29,42]){//0,2println(i)}

join(separator,sequence): 返回一个由给定的分隔符分离出来的序列的元素。

join(":",["A","B","C"])=="A:B:C"varlanguages=["Swift","Objective-C"]join("/",languages)=="Swift/Objective-C"

map(sequence,transformClosure): 如果transformClosure适用于所给序列中所有的元素，则返回一个新序列。

equal(map(1...3,{$0*5}),[5,10,15])foriinmap(1...10,{$0*10}){//10,i))}

max(comparable1,comparable2,etc.): 返回函数所给参数中的最大值。

max(0,1)==1max(8,2,3)==8

maxElement(sequence): 返回所给序列的同类元素中的最大元素。

maxElement(1...10)==10varlanguages=["Swift","Objective-C"]maxElement(languages)=="Swift"

minelements(sequence): 返回所给序列的同类元素中的最小元素。

minelement(1...10)==1varlanguages=["Swift","Objective-C"]minelement(languages)=="Objective-C"

reduce(sequence,initial,combineClosure): 从第一个初始值开始对其进行combineClosure操作，递归式地将序列中的元素合并为一个元素。

varlanguages=["Swift","Objective-C"]reduce(languages,"",{$0+$1})=="SwiftObjective-C"reduce([10,5],{$0*$1})==1000

reverse(sequence): 返回所给序列的倒序。

equal(reverse([1,3]),[3,1])foriinreverse([1,3]){//3,1println(i)}

startsWith(sequence1,sequence2):如果序列1和序列2的起始元素相等，则返回true。

 
 
 
  
startsWith("foobar","foo")==true
 
 
  
startsWith(10..100,10..15)==true
 
 
  
varlanguages=["Swift","Objective-C"]
 
 
  
startsWith(languages,["Swift"])==true 
 

 

原文地址：https://www.jb51.cc/swift/327001.html