逻辑中断
如果逻辑或左边为真,则中断,输出左边,不看
console.log(1 || 0 = 1)
console.log(1 || 2 = 1)
如果左边为假,则输出右边
console.log(0 || 2 = 2)
console.log(0 || false = false)
如果逻辑与左边为假,则中断,输出左边,不看右边
console.log(0 || 0 = 0)
console.log(0 || 1 = 0)
如果左边为真,则输出右边
console.log(1 || 0 = 0)
console.log(1 || 2 = 0)
隐式转换
- 有字符串的加法为拼接字符串 如:“” + 1 = “1”
- 减法只能用于数字,他会使空字符串" "转化为0
- null经过数字转换后会变成0
- undefined经过字符串后会变为NaN