export const isUndefined = (val: any): val is undefined =>
typeof val === 'undefined'
export const isNull = (val: any): val is null => val === null
/**
* 值不存在
*/
export const isNullOrUndefined = (val: any) => isNull(val) || isUndefined(val)
/**
* 值存在
*/
export const isNotNullOrUndefined = (val: any) => !isNullOrUndefined(val)
export const isBrowser = () => typeof window !== 'undefined'
export const isMobAgent = (userAgent: string) =>
/(phone|pad|pod|iPhone|iPod|ios|iPad|Android|Mobile|BlackBerry|IEMobile|MQQBrowser|JUC|Fennec|wOSBrowser|BrowserNG|WebOS|Symbian|Windows Phone)/i.test(
userAgent
) || userAgent.toLowerCase().indexOf('micromessenger') !== -1
export const isJSON = (str: string) => {
if (typeof str == 'string') {
try {
const obj = JSON.parse(str)
if (typeof obj === 'object' && obj) {
return true
} else {
return false
}
} catch (e) {
return false
}
} else {
return false
}
}
export const compareId = (a: string | number, b: string | number) => a == b