iOS基础【string和Array 互转】&【 string与class互转】& 【json string 和Array互转】

componentsSeparatedByString
componentsJoinedByString

NSClassFromString
NSStringFromClass

#字符串分割到数组里#
NSString *str = @"You@are@the@best";
NSArray *array7 = [str componentsSeparatedByString:@"@"];
//结果：array7 = @[@"You",@"are",@"the",@"best"];

#数组连接成字符串#
NSArray *array8 = @[@"I", @"love", @"you"];
NSString *str = [array8 componentsJoinedByString:@""];
//结果：str = @"Iloveyou"

/**


 应用场景：上传审核材料，接口参数AuditMaterials多张图用“|”隔开
 返回的字符串： 【数组arr元素对象的属性picurl 以“|”为分隔符进行拼接】
 */
+ (NSString *)getAuditMaterialsWithArr:(NSMutableArray *)arr{
    
    
    
    NSArray *arDistinct = [arr valueForKeyPath:@"@distinctUnionOfObjects.picurl"];//arDistinct是一些含有picurl属性的对象集合
    
    

//数组连接成字符串#
NSString *str = [arDistinct componentsJoinedByString:@"|"];
    
    
    return str;
    
}

  "AuditMaterials" : "\/M00\/00\/2F\/wKgUGmBRvuCAEkJdAACQUc0PHoc902.png|\/M00\/00\/2F\/wKgUGmBRvwCAeZNLAACQUc0PHoc345.png|\/M00\/00\/2F\/wKgUGmBRvuaABJmhAAFgZvkEjuQ542.png|\/M00\/00\/2F\/wKgUGmBRvvqAaNVyAAFgZvkEjuQ335.png|\/M00\/00\/2F\/wKgUGmBRvuyAF0XOAACQUc0PHoc150.png|\/M00\/00\/2F\/wKgUGmBRvtmAaLAjAACQUc0PHoc830.png|\/M00\/00\/2F\/wKgUGmBRvvOAG13hAABWLl_-9T0303.png|\/M00\/00\/2F\/wKgUGmBRvw6AVGCgAABWLl_-9T0305.png|\/M00\/00\/2F\/wKgUGmBRvtOARMnzAAAosisZbbk301.png",