//一、同步執行: async await 關鍵詞
調用方也得加 async
async testAsync() {
const result = await this.testPromise()
console.log('async test--', result)
},
testPromise() {
return new Promise((resolve, reject) => {
setTimeout(() => {
console.log('Promise handle')
resolve(1234)
}, 2000)
})
},
打印輸出
Promise handle
async test-- 1234
//二、簡單的
testPromise() {
return new Promise((resolve, reject) => {
setTimeout(() => {
console.log('Promise handle')
resolve(1234) //提前返回回去,表示正確數據 then res
//reject(33333) //提前返回回去,表示異常內容 catch err
}, 2000)
})
},
a:function(){
this.testPromise().then(res=>{
console.log(res)
}).catch(function(err){
console.log(err) //如果有 reject 則打印這個的值
})
}
打印:
1234
or
33333