obj = {
1: 'a',
2: 'b',
length: 2,
push: Array.prototype.push
}
obj.push('c')
console.log(obj.length) //3
console.log(obj[0]) // undefined
console.log(obj[1]) // a
console.log(obj[2]) // c
console.log(obj[3]) // undefined
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…