console 命令行工具 X clear

console

var number1=22;
var number2=33;
var myString="Heather"

var sum=number1+number2;
document.write(sum+"<br/>");

var sumString=number1+myString;
document.write(sumString+"<br/>");

var stringSum=number2+myString;
document.write(stringSum+"<br/>");

var stringNum=number1="";

var stringNumSum=stringNum+myString;
document.write(stringNumSum+"<br/>")

document.write('<br/>------------------------------<br/>');

var left=1;
var right=2;

left+=right;
document.write(left+"<br/>");

left-=right;
document.write(left+"<br/>");

left*=right;
document.write(left+"<br/>");

left/=right;
document.write(left+"<br/>");

document.write('<br/>--------------------------------<br/>');

left= (1+2)+3;
right=(3+4)+1;

document.write((left>right)+"<br/>");
document.write((left<right)+"<br/>");
document.write((left>=right)+"<br/>");
document.write((left<=right)+"<br/>");
document.write((left==right)+"<br/>");
document.write((left!=right)+"<br/>");

document.write('<br/>--------------------------------<br/>');

var logincOperation=false;

logincOperation=(left>right)&&(left<right);
document.write(logincOperation+"<br/>");

logincOperation=true &&(left<right);
document.write(logincOperation+"<br/>");

logincOperation=(left>right)||(left<right);
document.write(logincOperation+"<br/>");

logincOperation=(left>right)&& false;
document.write(logincOperation+"<br/>");

logincOperation=!(left>right);
document.write(logincOperation+"<br/>");

logincOperation=(left<right);
document.write(logincOperation+"<br/>");

document.write('<br/>--------------------------------<br/>');

document.write("Number('123'):"+Number("123")+"<br/>");
document.write("Number('3.1415'):"+Number("3.1415")+"<br/>");
document.write("Number('hao123'):"+Number("hao123")+"<br/>");
document.write("Number('100px'):"+Number("100px"));

document.write('<br/>--------------------------------<br/>');
document.write("parseInt('123'):"+parseInt("123")+"<br/>")
document.write("parseInt('3.1415'):"+parseInt("3.1415")+"<br/>");
document.write("parseInt('hao123'):"+parseInt("hao123")+"<br/>");
document.write("parseInt('100px'):"+parseInt("100px"));

document.write('<br/>--------------------------------<br/>');
document.write("parseInt('+123'):"+parseInt("+123")+"<br/>")
document.write("parseInt('-123'):"+parseInt("-123")+"<br/>")

document.write('<br/>--------------------------------<br/>');
document.write("parseFloat('123'):"+parseFloat("123")+"<br/>")
document.write("parseFloat('3.1415'):"+parseFloat("3.1415")+"<br/>");
document.write("parseFloat('hao123'):"+parseFloat("hao123")+"<br/>");
document.write("parseFloat('100px'):"+parseFloat("100px"));

document.write('<br/>--------------------------------<br/>');
var result=(2<1)?"小芳":"小美";
document.write(result);

document.write('<br/>--------------------------------<br/>');
var number=1;

//把数字转换成字符串
var stringNumber=1+"";

var stringNumber2=number.toString();
document.write(stringNumber+"<br/>");
document.write(stringNumber2+"<br/>");

//转义字符
alert("HI \"'Heather\'!\n Hello");

<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script>
        var number = 10;
        var a;
        var myString='Heather';
        var noSpace=null;
        var isReal=true;

        document.write(number+'<br/>');
        document.write(a+'<br/>');
         document.write(myString+'<br/>');
          document.write(noSpace+'<br/>');
           document.write(isReal+'<br/>');
    </script>
</head>
<body>
</body>
</html>