例如,你可以使用 if 语句来根据条件包含不同的 JSX 代码: let content; if (isLoggedIn) { content = <AdminPanel />; } else { content = <LoginForm />; } return ( {content} ); 如果你喜欢更紧凑的代码,可以使用 ? 条件运算符。与 if 不同,他能与 JSX 语法混合书写: {isLoggedIn ? (...
You can't provide if-else condition in the return block, make use of ternary block, also this.state will be an object, you shouldn't be comparing it with a value, see which state value you want to check, also return returns only one element, make sure to wrap them in a View render...
if, else, else if return ( { (() => { if('a'==='b') { return ( Hi ) } else if ('b'==='b') { return ( Hello ) } else { return ( Bye ) } })() } ) Note: Have to use an anonymous functions (also need to immediately invoke the function ) Switch ...
* returnFiber: 父亲节点 */functioncompleteUnitOfWork(unitOfWork:Fiber):void{letcompletedWork=unitOfWork;// 这里又是一个循环do{// 1. 判断任务是否完成, 完成就打个完成的标签, 没有完成就抛出异常// 2. 如果有兄弟节点, 那么接下来工作节点是该 xdif(completedWork.sibling!==null){workInProgress=sibling...
(parentComponent);if(container.context===null){container.context=context;}else{container.pendingContext=context;}// ...constupdate=createUpdate(expirationTime,suspenseConfig);// Caution: React DevTools currently depends on this property// being called "element".update.payload={element};callback=call...
next(value); if (data.done) { return; } else { data.value.then(x => { value = x; loop(); }) } } loop(); } This function takes any generator as an argument, and keeps calling next() on it as long as there are values to yield. In this case, the yielded values are ...
Only files inside the public folder will be accessible by %PUBLIC_URL% prefix. If you need to use a file from src or node_modules, you’ll have to copy it there to explicitly specify your intention to make this file a part of the build. When you run npm run build, Create React App...
<Else /> Can contain any number of elements inside, which it renders as-is. It can also contain a function. Should not be used outside of an<If />block. It will only be displayed, if parentIfblock's condition is false. A container for<Case condition={...}/>and<Default />blocks...
/** 1896 * something else is the responder right now and will not release it 1897 */ 1898 onresponderreject?: ((event: gestureresponderevent) => void ) | undefined ; 1899 1900 /** 1901 * if the view is responding, the following handlers can be called: 1902 */ 1903 1904 /** ...
} else { NSString *message = [NSString stringWithFormat:@"Could not find image %@", imageURL]; RCTLogWarn(@"%@", message); completionHandler(RCTErrorWithMessage(message), nil); } }); return ^{ cancelled->store(true); }; } This.. Like and Love , if it work 👍 👎 5 😕 ...