1) #define宏定义有一个特别的长处:可以使用 #ifdef ,#ifndef等来进行逻辑判断,还可以使用#undef来取消定义。 2) typedef也有一个特别的长处:它符合范围规则,使用typedef定义的变量类型其作用范围限制在所定义的函数或者文件内(取决于此变量定义的位置),而宏定义则没有这种特性。 4、别人总结的用途: 用途一: 定...
typedef char * PSTR; #define DEFCHAR char* ... char string[10] = "abcde"; const DEFCHAR p1 = string;//字符首地址 const PSTR p2 = string; p1++; //ok p2++; //error printf("%c %c\n",*p1,*p2); 通过编译运行可知:p2++出错。 分析: 这个问题再一次提醒我们:typedef和#define不同,...
Type 'Object' gives autocomplete. It includes all the methods which an empty object can have. But empty object without Object type has not. If we try to assign a value to empty object, we get error: In order to do it, we can do: constobject: { [key:string]: any } ={};object....
复制 import"reflect-metadata";constformat:(formatter:string)=>PropertyDecorator=(formatter)=>{return(target:Object,propertyKey:string|symbol)=>{Reflect.defineMetadata(propertyKey,formatter,target)}}classGreeter{@format("Hello, %s")greeting:string;constructor(message:string){this.greeting=message;}greet(...
// 转译后的Javascriptdefine(["require","exports"],function(require,exports) {"use strict";Object.defineProperty(exports,"__esModule", {value:true});varGEO_LEVEL; (function(GEO_LEVEL) {GEO_LEVEL[GEO_LEVEL["NATION"] =1] ="NATION";GEO_LEVEL[GEO_LEVEL["PROVINCE"] =2] ="PROVINCE";GEO_...
To define an object type, simply enumerate its attributes and types. For example, the following is a function that accepts an object type as a parameter: // 参数的类型注解是一个对象类型 function printCoord(pt: { x: number; y: number }) { console.log("The coordinate's x value is " ...
description:对方法的定义,与define functiongetNameDecorator(target:any,key:string){console.log('target is',target,'key',key)}classTest{name:string;constructor(name:string){this.name=name}@getNameDecoratorgetName(){returnthis.name}}consttest=newTest('cyy')//out put:// target is Test { get...
Normally, when you assign an object directly to a variable with a giventypein TypeScript, you benefit from something called “excess property checks.” These checks will warn you if you add any unexpected keys to an object as you define it. ...
greeting以及成员方法showGreeting 五.实践规范除了遵循基本的语法格式外,实践中还应该遵守这些规范约束:用基础类型(number, string, boolean, object)...的可选参数没必要在类型上标出来,因为callback允许少传/不传参数函数重载需要注意声明顺序,应该从特殊到一般自上而下排列(例如any会短路其它重载声明,类似于...
(function(root,factory){if(typeofdefine==="function"&&define.amd){define(["libName"],factory);}elseif(typeofmodule==="object"&&module.exports){module.exports=factory(require("libName"));}else{root.returnExports=factory(root.libName);}}(this,function(b){ ...