let matchNumberStr = ['0',]
// 部分关键字转换为boolean值
let falseField = ['false','False','FALSE','null','Null','NULL','undefined','Undefined'];
let trueField = ['true','True','TRUE'];
// 类型转换
function toString(){
    // 情况1 非对象,直接调用内部值
}

// 转换为number类型,先用toBoolean转换为布尔类型
function toNumber(v){
    if(isString(v)){
        if(falseField.includes(v)){
            v = toBoolean(v)
        }else if (trueField.includes(v)){
            v = toBoolean(v)
        }
    }
    if(!v){
      return 0;
    }
    let r = Number(v);
    return isNaN(r)?0:r;
}

// 考虑字段类型
function toBoolean(v){
    // 字符串类型
    if (isString(v)){
        if(falseField.includes(v)){
            return false
        }else if (trueField.includes(v)){
            return true
        }else{
            Boolean(v)
        }
    }
}

function isArray(v){
    return v instanceof Array
}
function isString(v){
    return v instanceof String || typeof v === 'string'
}
function isNumber(v){
    return v instanceof Number
}
function isObject(v){
    return v instanceof Object
}

// 判断 obj 或者 arr 是否为空 , 允许为0, 不允许空字符串
function isEmpty(v){
    if(isArray(v)){
        return v.length === 0
    }else if(isObject(v)){
        return Object.keys(v).length === 0
    }else if(v === 0){
        return false;
    }else{
        return !v
    }
}

// 判断数据是否存在,不允许为空字符串,空对象与空数组, 允许为 0

module.exports = {
    toNumber,
    toString,
    toBoolean,
    isEmpty
}