Promise在await报错后,如何继续往下跑...

时间:2022-01-27 00:09:04

一、resolve

当a>0时,正常情况依次输出A、B、C

	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);
}
});
}

Promise在await报错后,如何继续往下跑...

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。

	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);
}
});
}

Promise在await报错后,如何继续往下跑...

三、catch

增加catch处理错误,程序可以继续执行

	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

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

  

Promise在await报错后,如何继续往下跑...

四、使用then处理错误,程序继续执行

换一种写法,使用then。

	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);
}
});
}

Promise在await报错后,如何继续往下跑...

五、在await处使用catch,程序继续执行

    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);
}
});
}

Promise在await报错后,如何继续往下跑...

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

    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)});
}

  

Promise在await报错后,如何继续往下跑...