例1：循环赋值  a1=1，a2=2，a3=3，a4=4...a100=100

for (var i = 0; i < count; i++) {
　　eval(‘a‘+j+ ‘="‘+ (i+1) + ‘"‘);
};

例2：循环赋值  aa=1，ab=2，ac=3，ad=4...az=26;

for (var i = 0; i < count; i++) {
　　eval( ‘a‘+String.fromCharCode(97+i)+ ‘="‘+ (i+1) + ‘"‘ );
};

String.fromCharCode(97+i)代表从小写a开始

String.fromCharCode(65+i)代表从大写a开始

js循环变量赋值