1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <title></title> 6 <script type="text/javascript"> 7 8 var n1=10; 9 var n2=20; 10 11 var n = n1++; //n1 = 11 n1++ = 10 12 13 console.log('n='+n); // 10 14 console.log('n1='+n1); //11 15 16 n = ++n1 //n1 = 12 ++n1 =12 17 console.log('n='+n); //12 18 console.log('n1='+n1); //12 19 20 n = n2--;// n2=19 n2--=20 21 console.log('n='+n); //20 22 console.log('n2='+n2); //19 23 24 n = --n2; //n2=18 --n2 = 18 25 console.log('n='+n); //18 26 console.log('n2='+n2); //18 27 28 29 </script> 30 </head> 31 <body> 32 </body> 33 </html>