grammar pretest

1.方法与顺序无关2.枚举绑定数据类型enum{ObjectiveC,Java,Ruby,Python,Erlang};typedefNSUIntegerLanguage;3.属性不用写@synthesize4.语法简化4.1NSNumberNSNumber*value;value=@12345;value=@123.45f;value=@123.45;value=@YES;4.2NSArrayNSArray*array;array=@[];//空数组array=@[a];//一个对象的数组array=@[a,b,c];//多个对象的数组4.3NSDictionaryNSDictionary*dict;dict=@{};//空字典dict=@{k1:o1};//包含一个键值对的字典dict=@{k1:o1,k2:o2,k3:o3};//包含多个键值对的字典 注：对可变的容器，可以用：NSMutableArray*mutablePlanets=[@[@"Mercury",@"Venus",@"Earth",@"Mars",@"Jupiter",@"Saturn",@"Uranus",@"

1. Quickly create NSNumber objectsNSNumber *number1 = @20; @ + constantint a = 20;NSNumber *number2 = @ (a); @ + (variable)2. Quickly create a string object that converts the C-language string constant to OCNSString *str1 = @ "Frank";3. Quickly create Nsarry objectsNsarray *arr1 = @[@ "AA", @ "Hu", @ "Ty", @ "FD"];4. Quickly create Nsmutablearry objectsNsmutablearray *ARR2 = [@[@ "DG", @ "Ji", @ "GT", @ "FG"] mutablecopy];5. Quickly remove elements from the array according to subscriptNSString *

Swift Classic Grammar Summary1: function 1.1 Func Funcnmae () {} This defines a function whose arguments are null, the return value is NULL, and if the parameters and return values are written directly in two brackets. The 1.2 parameter needs to indicate the type, and if no return value can be not written (), the return value only needs to write the return type, and if the return name is written, the value after the function call can be a

NSNumber *number1 = @20; @ + constantint a = 20;NSNumber *number2 = @ (a); @ + (variable)2. Quickly create a string object that converts the C-language string constant to OCNSString *str1 = @ "Frank";3. Quickly create Nsarry objectsNsarray *arr1 = @[@ "AA", @ "Hu", @ "Ty", @ "FD"];4. Quickly create Nsmutablearry objectsNsmutablearray *ARR2 = [@[@ "DG", @ "Ji", @ "GT", @ "FG"] mutablecopy];5. Quickly remove elements from the array according to subscriptNSString *str2 = arr1[0];NSString *STR3 = ar

PHP Learning Notes (i): basic grammar markers, blanks, and annotations, learning the basic grammar of notes First, PHP tags 1. XML styleCopy the Code code as follows:2. Short styleCopy the Code code as follows:3. Script StyleCopy the Code code as follows: Second, PHP comments 1. Single-line Comment://(C + + style)2. Multiline Comment:/* */(c-style)3. Single-line script Comment: # (shell style) Tips: Notes

HTML5 grammar basic learning notes, html5 grammar learning notes 1. Line StyleAdd a style to a separate label.Advantage: it is easier to add attributes instantly.Disadvantage: It is very troublesome to modify the attributes one by one. 2. inline Style SheetsAdvantage: valid for the current HTML file.Disadvantage: it is complicated to modify multiple pages. 3. External Style Sheets Border:Border composition:

Three basic factors for advanced programming languages:Syntax: A constituent rule that describes the composition of a language (including lexical rules and grammatical rules)Semantics: Describing the meaning of grammatical componentsPragmatics: A method for describing the use of grammatical componentsFormal language theory (formal language theory) is a mathematical approach to the generation, general nature and rules of natural languages (such as English) and artificial languages (such as progra

In 1956, Noam Chomsky divided the distribution into four types based on the different rows that imposed restrictions on the production formula and defined the corresponding four formal languages, as follows: Grammar type Generate limit Grammar Language Type 0 Grammar α → βAlpha and beta belong to (vtuvn) *, and Alpha length is not 0

Compilation principles: This part of the Chinese method is very important. It is also involved in the soft test. At the beginning, this part of the content is quite messy. I can't even understand the definition, so let alone differentiate them. This is a question, analyze the questions, contact the definitions, and discuss them with the students. The relationship between them is shown in the figure below. 1. Grammar

For grammar G = (V, T, S, P), if the form of the formula is as follows: A-> XBA-> X Where a and B belong to V, and X belongs to T *, which is called the right linear syntax. Similar, if the form of the formula is as follows: A-> BXA-> X It is called the left linear grammar. The right and left linear grammar are collectively referred toRegular syntax. Regula