判断一个字符串是否是整形||浮点型

//判断是否为整形：
- (BOOL)isPureInt:(NSString*)string{
    NSScanner* scan = [NSScanner scannerWithString:string];
    int val;
    return[scan scanInt:&val] && [scan isAtEnd];
}

//判断是否为浮点形：
- (BOOL)isPureFloat:(NSString*)string{
    NSScanner* scan = [NSScanner scannerWithString:string];
    float val;
    return[scan scanFloat:&val] && [scan isAtEnd];
}