JS,javascript 如何把普通数组转换成JSON数组?

Question

A = ['NAME:"XXXX",'YEAR:1990','OLD:21']
A[0]="name:'XXX'"
A[1]="YEAR:1990"
A[2]="OLD:BB";

如何转换成
B={
NAME:'XXXX',
YEAR:1990,
OLD:21
};