var s1 = {} var s2 = undefined var s3 = null var s4 = "" if(s1) console.log(‘true‘) //只有 {} 被识别为false if(s2) console.log(‘true‘) if(s3) console.log(‘true‘) if(s4) console.log(‘true‘)
算法辅助(js)
原文:https://www.cnblogs.com/lhx9527/p/13948016.html