iOS 判断字符串是否为空

经常性我们会用到字符串判空，如下

#import "NSString+Tools.h"

@implementation NSString (Tools)
+ (BOOL)isBlankString:(NSString *)aStr {
    if (!aStr) return YES;
    if ([aStr isKindOfClass:[NSNull class]]) return YES;
    if (![aStr isKindOfClass:[NSString class]]) return YES;
    if (!aStr.length) return YES;
    return NO;
}

@end

但是有时候我们从服务器获取数据的时候不一定为string所以做了一点优化

+ (BOOL)isBlankString:(NSString *)aStr {
    if (!aStr) return YES;
    if ([aStr isKindOfClass:[NSNull class]]) return YES;
    if (![aStr isKindOfClass:[NSString class]]){
        NSString *tempStr = [NSString stringWithFormat:@"%@",aStr];
        aStr = tempStr;
    }
    if (!aStr.length) return YES;
    return NO;
}
+ (NSString *)getString:(NSString *)aStr {
    if ([self isBlankString:aStr]) {
        return @"";
    }
    return [NSString stringWithFormat:@"%@",aStr];
}