Differences between IsNaN and number.isnan in JS

1）isNaN

• In order to judge whether the value of a calculation result or variable NaN
• isNaN（value）：value Indicates the detected value
• The judgment process ： First, type detection , If the parameter passed in is not of numeric type , The second step is to convert the passed in parameter to numeric type , Then whether it is NaN The judgment of the

        console.log(isNaN(NaN));//true
        console.log(isNaN(true));//false
        console.log(isNaN('aaa'));//true
        console.log(isNaN(null));//false
        console.log(isNaN(''));//false
        console.log(isNaN(undefined));//true

2）Number.isNaN The process of judgment ： First, type detection , If the parameter passed in is not of numeric type , Go straight back to false If the judgment is numeric , And then use isNaN Judge in a way

        console.log(Number.isNaN(NaN));//true
        console.log(Number.isNaN(true));//false
        console.log(Number.isNaN('aaa'));//false
        console.log(Number.isNaN(null));//false
        console.log(Number.isNaN(123));//false
        console.log(Number.isNaN(undefined));//false