方法一：
var htmlstr = ‘
for( var i = 1 ; i < 10 ; i++ ){
htmlstr += ‘’;
for(var j = 1 ; j < 10 ; j++){
if(j<=i){
htmlstr += ‘’+i+’’+j+’=’+ij+’’;
}
}
htmlstr += ‘’;
}
htmlstr += ‘’;
document.write(htmlstr)
方法二：
document.write(’
’);for (var i = 1 ; i < 10 ; i++){
document.write(’’);
for (var j = 1 ; j < 10 ; j++){
if(j<=i){
document.write(’’+i+’’+j+’=’+ij+’’)
}
}
document.write(’’);
}
document.write(’’