手机号、身份证号转星号

.h文件

@interface AsteriskTool : NSObject

//把手机号第4-7位变成星号
+(NSString *)phoneNumToAsterisk:(NSString*)phoneNum;

//把身份证号第5-14位变成星号
+(NSString *)idCardNumToAsterisk:(NSString *)idCardNum;
@end

.m文件

@implementation AsteriskTool

+(NSString *)phoneNumToAsterisk:(NSString *)phoneNum
{
    return  [phoneNum stringByReplacingCharactersInRange:NSMakeRange(3, 4) withString:@"****"];
}

+(NSString *)idCardNumToAsterisk:(NSString *)idCardNum
{
    return [idCardNum stringByReplacingCharactersInRange:NSMakeRange(4, 10) withString:@"**********"];
}

@end