swift基础知识1

最近在学习swift,把我学习内容分享给跟我一样在学习swift的小伙伴。


import UIKit

class ViewController: UIViewController {

override func viewDidLoad() {

super.viewDidLoad()

self.title = "基本用法"

self.base();

}

func base() {

//1.变量和常量

let i:Double = 10.5          //:后面跟这个变量的类型

let j:Double = 20.6

var k:Int = Int(i) + Int(j)  //let 不可更改的变量  var 可以被修改的变量

print(k);

//2. 条件语句

if k == 30 {                  //if之后不需要跟(),直接跟判断的条件

k = 50

print(k)

}

//3.四种for写循环的方式

for var i = 0; i < 10; i++ {

print("1",i)

}

for i in 0..<10 {

print("2",i)

}

for i in 0...10 {

print("3",i)

}

for _ in 0...10 {

print("hello")

}

//4.字符串

let word:String = "qqheillow"

//遍历字符串

for i in word.characters {

print(i)

}

//字符串拼接

var word1 = word + "hellow"

print(word1)

word1 = word1 + "hei myfriend"

print(word1)

var str:NSString = "qqqwww"

var str1:NSString = "eeerrr"

//拼接

str = str.stringByAppendingFormat(str1, 0)

print(str)

str = str.stringByAppendingString(str1 as String)

print(str)

str1 = (str as String) + (str as String)

print(str1)

//替代

str = str.stringByReplacingCharactersInRange(NSMakeRange(0, 4), withString: "eee")

print(str)

//      5.数组,不可变数组不能增加元素

let array:NSArray = ["123","234"]

for arr in array {

print(arr)

}

let arr = NSArray(array: ["1","2","3"])

print(arr)

//数组,可变数组

let marray:NSMutableArray = ["1","2"]

//添加元素

marray.addObject("123")

print(marray)

marray.addObject("11233")

//移除最后一个元素

marray.removeLastObject()

//在指定位置插入指定元素

marray.insertObject("333", atIndex: 2)

print(marray)

//删除制定位置的元素

marray.removeObjectAtIndex(0)

print(marray)

//代替制定位置的元素

marray.replaceObjectAtIndex(1, withObject: "1111")

print(marray)

//数组之间拼接

marray.addObjectsFromArray(["11123","3333333"])

print(marray)

//6.字典

//不可变字典

let dic:NSDictionary = ["name":"wlx","age":"23","tall":"165cm"]

print(dic)

let dict:NSDictionary = NSDictionary(dictionary: ["name":"wlx","age":"23","tall":"165cm"])

print(dict)

let ddict = NSDictionary(dictionary: dict)

print(ddict)

//可变字典

let mdict = NSMutableDictionary(dictionary: ["2":"a"])

mdict.setObject("b", forKey: "1")

print(mdict)

let mmdic = NSMutableDictionary()

//增加元素

mmdic.setObject("11123", forKey: "abc")

mmdic.setObject("11124", forKey: "qwe")

mmdic.setObject("11125", forKey: "rty")

mmdic.setObject("11126", forKey: "dfg")

print(mmdic)

//删除元素

mmdic.removeObjectForKey("abc")

print(mmdic)

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

// Dispose of any resources that can be recreated.

}

}


后续会持续更新我的学习内容。一直到各种控件的基本使用,闭包,代理的使用等等。如果有什么错误,欢迎指出,期待共同进步。

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