let str = 'hello world'//如截取hello//indexOf,查找字符串,有返回下标,没有返回-1let index = str.indexOf('hello')//substring,参数是从哪截取到哪,不接受负数let cutOut1 = str.substring(index, index + 5)//substr,参数是从哪截取几个let cutOut2 = str.substr(index, 5)//slice,参数是参数是从哪截取到哪,可以负数let cutOut3 = str.slice(index, index + 5)
1200字范文,内容丰富有趣,写作的好帮手!