安装使用

pod 'YZExtension', '~> 2.0.0'

github demo

说明

在使用数组或者字典、字符串时，经常遇到越界或者nil对象引起的闪退，在庞杂的项目中，无法逐个排查。
采用 method swizzling实现这类异常得到修复，在运行中，不能出现闪退

数组越界取值

NSMutableArray *list = [NSMutableArray new];
id object = [list objectAtIndex:1000];
NSLog(@"%@",object);// 0x600000446e70 [__NSArrayM objectAtIndex:] index 1000 beyond bounds [0 .. 0]

数组插入nil对象

NSMutableArray *list = [NSMutableArray new];
[list insertObject:nil atIndex:0];
// 0x600000446e70 [__NSArrayM insertObject:atIndex:] object cannot be nil
[list replaceObjectAtIndex:0 withObject:nil];
// 0x600000448220 [__NSArrayM replaceObjectAtIndex:withObject:] object cannot be nil

NSArray *array = @[@"aa",text,@"ccc"];
// 0x6000000031f0 [__NSPlaceholderArray initWithObjects:count:] attempt to insert nil object from objects[1]
NSLog(@"%@",array);
/* (
aa,
ccc
) */

字典添加nil对象

NSString *text = nil;
[list addObject:@{@"name":text}];
NSDictionary *dic = @{@"name":@"aaa",@"age":text,@"sex":@"man"};
// 0x600000003230 [__NSPlaceholderDictionary initWithObjects:forKeys:count:] attempt to insert nil object from objects[1]
NSLog(@"%@",dic); 
/* {
name = aaa;
sex = man;
} */

字典设置 key、object 为nil对象

NSMutableDictionary *dict = [NSMutableDictionary new];
[dict setObject:nil forKey:@"test"];
[dict setObject:@"object" forKey:text];
// 0x60400023a060 [__NSDictionaryM setObject:forKey:] key cannot be nil (object: object)
// 0x60400023a060 [__NSDictionaryM setObject:forKey:] object cannot be nil (key: test)

NSString 截取越界

NSString *tmp = @"hello wrold";
NSString *p = [tmp substringFromIndex:100];
p = [tmp substringToIndex:300];
p = [tmp substringWithRange:(NSRange){20,40}];