<! DOCTYPEhtml>  
<html lang="en">  
<head>  
    <meta charset="UTF-8">  
    <title>Javascript conversions between different types of data operations</title>
</head>  
<body>
<script type="text/javascript">
    var result = null + 1;
    console.log(result);  / / 1

    result = undefined + 1;
    console.log(result);  //NaN

    result = false + 1;
    console.log(result);  / / 1

    result = true + 1;
    console.log(result);  / / 2

    result = '6' + 1;
    console.log(result);  / / 61

    result = '6' - 1;
    console.log(result);  / / 5

    result = 'a' + 1;
    console.log(result);  //a1       

    result = 'a' - 1;
    console.log(result);  //NaN   

    result = null + undefined;
    console.log(result);  //NaN

    result = null + 'a';
    console.log(result);  //nulla

    result = null - 'a';
    console.log(result);  //NaN

    result = undefined + 'a';
    console.log(result);  //undefineda    

    result = undefined - 'a';
    console.log(result);  //NaN  

    result = true + 'a';
    console.log(result);  //truea  

    result = true - 'a';
    console.log(result);  //NaN 

    result = false + 'a';
    console.log(result);  //falsea      

    result = 66 + 'a';
    console.log(result);  //66a      

    result = null + false;
    console.log(result);  / / 0

    result = null + true;
    console.log(result);  / / 1

    result = true + false;
    console.log(result);  / / 1


    result = false - true;
    console.log(result);  / / 1

    result = true + undefined;
    console.log(result);  //NaN   

    result = false + undefined;
    console.log(result);  //NaN  

    result = 1 + NaN;
    console.log(result);  //NaN 

    result = 'a' + NaN;
    console.log(result);  //aNaN     

    result = 1 + 2 + '3';
    console.log(result);  / / 33

    result = 1 + (2 + '3');
    console.log(result);  / / 123

    result = 1 + true + undefined + 's'; // 1+1+NaN+'s'=2+NaN+'s'=NaN+'s'=NaN
    console.log(result);  //NaNs

</script>
</body>  
</html>  
Copy the code


\

\

\

\