Swift Basic use Method (one of swift development)

Last night Apple unveiled a new generation of programming languages Swift, which officially provided a ibook documentation. There is a need to be able to see.

Address: https://itunes.apple.com/cn/book/swift-programming-language/id881256329?mt=11


The following I first say some of the main things, we are just looking, so I will inevitably appear to understand the wrong place. Welcome to point out. Of course you can also read the official documents directly.


I. Basic types of Let,var

Let: constant, cannot be assigned two times. You can assign a value without specifying a type, and the compiler will infer it on its own initiative. The type can also be specified manually.

var: variable

Let A = 12//Declaration A is constant 12, type intlet b:double = 12//Declaration A is constant 12, manually specify type Double

Second, string

1, the plus can be directly stitching strings. Cannot directly splice other types into string

Let str = "Hello, playground." Let name = "Tom" let count = 10let say = str + name + String (count)  //"Hello, playground." Tom 10 "

2. Introduce code directly into the string

Let A = 1let b = 2let say = "The number was \ (A + B)"  //"The number is 3"

Third, arrays, dictionaries can be directly using the [] Declaration

1. Arrays

var arr = ["Catfish", "water", "tulips", "Blue paint"]arr[1] = "bottle of Water"//Change the second arr//["Catfish", "bottle of Wat Er "," tulips "," Blue paint "]

2. Dictionaries

var man = [    "like": "Apple",    "name": "Tom",]man["iphone"] = "5s"  //Add field man["like"] = "Mac"  //change field man// ["iphone": "5s", "like": "Mac", "name": "Tom"]

Iv. Control Statements

1, if can not directly use a variable or constant as a condition, must be an inference statement

Let A = 12if a > 0 {    //does something} else {   //do something}

Suppose you write if a {}, you will get an error, you cannot infer bool directly using a variable or constant


2. For

For I in 0..3 {   //i = 0, 1, 2}for var i = 0; i < 3; ++i {    //i = 0, 1, 2}//array Let scores = [1, 2, 3, 4, 5]for  Score in scores {    //score}//dictionary Let numsdic = [    "a": [2, 3, 5, 7, one, +],    "B": [1, 1, 2, 3, 5, 8],    "C": [1, 4, 9, 25],]for (key, numbers) in Numsdic {= number in    numbers {        //number    }}

3. While

var n = 2while N < {    n = n * 2}var m = 2do {    m = m * 2} while M < 100

Swift Basic use Method (one of swift development)