策略模式代替if-else

采用key-value的形式替换繁琐的if-else (高端大气上档次)

if-else或switch写法：

// if-else
const onTabChange = (key: string) => {
    
    if(key=="home") setTabContent(<Home />)
    else if(key=="search") setTabContent(<Search />)
    else if(key=="article") setTabContent(<Article />)
    else if(key=="video") setTabContent(<Video />)
  }

// switch
const onTabChange = (key: string) => {
    
	switch (key) {
    
	    case "home":
	        setTabContent(<Home />);
	        break;
	    case "search":
	        setTabContent(<Search />);
	        break;
   	    case "article":
	        setTabContent(<Article />);
	        break;
   	    case "video":
	        setTabContent(<Video />);
	        break;
	    default:
	    	return false;
	        break;
}

策略模式改造：

const onTabChange = (key: string) => {
    
    const tab = {
    
      "home": <Home />,
      "search": <Search />,
      "article": <Article />,
      "video": <Video />,
    }
    setTabContent(tab[key]);
  }