// 阻塞处理functionupdb1(){varstart=newDate().getTime();while(newDate().getTime()<start+3000);}updb1();console.log("updb1 success.");console.log("I like javascript.");
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// 非阻塞处理functionupdb2(done){setTimeout(()=>{done();},3000);}updb2(function(){console.log("updb2 success.");});console.log("I like javascript.");