Promise在await报错后，如何继续往下跑... 4年前

 一、resolve

当a>0时，正常情况依次输出A、B、C

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console.log("A");
    let result = await this.test();
    console.log("C:",result);

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = 3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        });
    }

二、没有处理失败信息，导致程序无法继续执行

当a<0时。输出A、B后，C无法输出，程序无法继续往下执行。

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console.log("A");
    let result = await this.test();
    console.log("C:",result);

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        });
    }

三、catch

增加catch处理错误，程序可以继续执行

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console.log("A");
    let result = await this.test();
    console.log("C:",result);

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        }).catch((err)=>{
            console.log("err:", err);
        });
    }

这样也可以

copy
let result = await this.test().catch(()=>{});

四、使用then处理错误，程序继续执行

 换一种写法，使用then。

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console.log("A");
    let result = await this.test().then((res)=>{
        console.log("success:", res);
    },(res)=>{
        console.log("fail:", res);
    });
    console.log("C:",result);


    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        });
    }

五、在await处使用catch，程序继续执行

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protected async createGameScene() {
        console.log("A");
        let result = await this.test().catch((err)=>{console.log("err:",err)});
        console.log("C:",result);
    }

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        });
    }

六、在test里catch后，程序会不执行then的reject，而是resolve。

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protected async createGameScene() {
        console.log("A");
       let result = await this.test().then((res)=>{
           console.log("C:",res);
       },(res)=>{
           console.log("D:",res)
       }).catch((err)=>{console.log("E:",err)});
    console.log("F:",result);
    }

    private  test(){
        return new Promise((resolve,reject)=>{
            console.log("B");
            let a = -3;
            if(a > 0){
                resolve(a);
            }else{
                reject(0);
            }
        }).catch((err)=>{console.log("test err:", err)});
    }