【js小题】用setTimeout实现SetInterval、手写compose

1.用setTimeout实现SetInterval

function mysettimeout(delay,fn,...args){let time=null;function tick(){time = setTimeout(()=>{fn(...args);tick();},delay)}fn(...args);tick();return ()=>clearTimeout(time);
}

当你需要停止这个循环定时器时

const stop = mysettimeout(1000, console.log, 'Hello World');
// 当你想停止循环时，调用返回的函数
stop();

2.手写一个compose函数，返回一个函数，能够对传入的不定量个函数进行链式调用
详见

function compose(...args){if(args.length){if(args.length===1){return ()=>args[0];}else return args.reduce((a,b)=>(...arg)=>a(b(...arg)))}else return (arg)=>arg;
}