Detailed explanation of how to use several timers in CocosCreator

setTimeout(()=>{console.log("abc"); }, 3000);

let timeIndex;
timeIndex = setTimeout(()=>{console.log("abc"); }, 3000);
clearTimeout(timeIndex);

@ccclass
export default class Helloworld extends cc.Component {
 
    private a = 1;
 
    start() {
        setTimeout(this.test, 3000);
    }
 
    private test(){
        console.log(this.a); //output undefined
        console.log(this); //Window
    }
}

@ccclass
export default class Helloworld extends cc.Component {
 
    private a = 1;
 
    start() {
        setTimeout(()=>{this.test()}, 3000);
    }
 
    private test(){
        console.log(this.a); //output 1
        console.log(this); //Helloworld
    }
}

setInterval(()=>{console.log("abc"); }, 1000);

let timeIndex;
timeIndex = setInterval(()=>{console.log("abc"); }, 1000);
clearInterval(timeIndex);

schedule(callback: Function, interval?: number, repeat?: number, delay?: number): void;

this.schedule(()=>{console.log("abc")},1,5,3);

private count = 1;
 
start() {
     
    this.schedule(this.test,1,5,3);
 
    this.unschedule(this.test);
}
 
private test(){
    console.log(this.count);
}

start() {
    let scheduler:cc.Scheduler = cc.director.getScheduler();
    scheduler.enableForTarget(this);
    //After a delay of 3 seconds, output 1, and then output 1 every 1 second, repeat 3 times. A total of 1+3 outputs are output scheduler.schedule(this.test1, this, 1, 3,3, false);
    //After a delay of 3 seconds, output 1, and then output 1 every 1 second, repeating infinitely scheduler.schedule(this.test2, this, 1, cc.macro.REPEAT_FOREVER,3, false);
}
 
private test1(){
    console.log("test1");
}
 
private test2(){
    console.log("test2");
}

//Delete the timer scheduler.unschedule(this.test1, this);