安全获取对象属性值

getAttrSafe.js

function getAttrSafe(obj, keyChain, delimiter) {
    delimiter = delimiter || '.';
    if (!keyChain) { throw Error('keyChain should not be a empty value')};

    var keys = keyChain.split(delimiter);
    console.log(keys);
    try {
        for (var i = 0; i < keys.length; i++) {
            obj = obj[keys[i]]
            if (obj === undefined) { return null;};
        };
        return obj;
    } catch (err) {
        return null;
    }
}

测试：
var aa={x:[{},{d:'x1d'}]}; getAttr(aa, 'x.0.d');