OC 判断一个字符串是不是int、float、double

//整形判断(整形返回yes ,否则为no)

- (BOOL)isPureInt:(NSString *)string{

    NSScanner* scan = [NSScannerscannerWithString:string];

    int val;

    return [scan scanInt:&val] && [scan isAtEnd];

}

//浮点形判断(整形/浮点型等数字均会返回YES,其他为no):

- (BOOL)isPureFloat:(NSString *)string{

    NSScanner* scan = [NSScannerscannerWithString:string];

    float val;

    return [scan scanFloat:&val] && [scan isAtEnd];

}

//浮点形判断(整形/浮点型等数字均会返回YES,其他为no):

- (BOOL)isPureDouble:(NSString *)string{

    NSScanner* scan = [NSScannerscannerWithString:string];

    double val;

    return [scan scanDouble:&val] && [scan isAtEnd];

}