思路：既然我們需要改變NSArry和NSDictionary的系統(tǒng)類方法，所以我們可以利用運行時runtime來進(jìn)行方法交換狂鞋、另一種方法就是通過添加分類來重寫類方法的實現(xiàn)片择。注意：這里不是添加類擴(kuò)展。

為NSArry和NSDictionary添加分類

Object-C file.png

category.png

分類中的實現(xiàn)：
方式一：
刪除.h文件（因為在項目里打印字典或數(shù)組時骚揍，使用的是系統(tǒng)的方法并不需要導(dǎo)入分類的頭文件）字管，.m文件下的實現(xiàn)啰挪，

#import <Foundation/Foundation.h>

@implementation NSDictionary (Log)

//重寫系統(tǒng)的方法控制輸出
-(NSString *)descriptionWithLocale:(id)locale indent:(NSUInteger)level
{
    NSMutableString *string = [NSMutableString string];
    
    //{}
    [string appendString:@"{"];
    
    //拼接key--value
    [self enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
        [string appendFormat:@"%@:",key];
        [string appendFormat:@"%@,",obj];
        
    }];
    [string appendString:@"}"];
    
    //刪除逗號
    //從后往前搜索 得到的是搜索到的第一個符號的位置
    NSRange range = [string rangeOfString:@"," options:NSBackwardsSearch];
    if (range.location != NSNotFound) {
        [string deleteCharactersInRange:range];
    }
    
    return string;
}

@end

@implementation NSArray (Log)

//重寫系統(tǒng)的方法控制輸出
-(NSString *)descriptionWithLocale:(id)locale indent:(NSUInteger)level
{
    //    return @"你大爺是你大姐";
    NSMutableString *string = [NSMutableString string];
    
    //{}
    [string appendString:@"["];
    
    //拼接obj
    [self enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        [string appendFormat:@"%@,\n",obj];
    }];

    [string appendString:@"]"];
    
    //刪除逗號
    //從后往前搜索 得到的是搜索到的第一個符號的位置
    NSRange range = [string rangeOfString:@"," options:NSBackwardsSearch];
    if (range.location != NSNotFound) {
        [string deleteCharactersInRange:range];
    }

    return string;
}

@end

方式二：
.h文件

#import <Foundation/Foundation.h>

@interface NSArray (desc)

@end


@interface NSDictionary (desc)

@end

.m文件

#import "NSArray+desc.h"

@implementation NSArray (desc)

- (NSString *)descriptionWithLocale:(id)locale
{
    NSMutableString *strM = [NSMutableString stringWithString:@"(\n"];
    
    [self enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        [strM appendFormat:@"\t%@,\n", obj];
    }];
    
    [strM appendString:@")"];
    
    return strM;
}

@end

@implementation NSDictionary (desc)

- (NSString *)descriptionWithLocale:(id)locale
{
    NSMutableString *strM = [NSMutableString stringWithString:@"{\n"];
    
    [self enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        [strM appendFormat:@"\t%@ = %@;\n", key, obj];
    }];
    
    [strM appendString:@"}\n"];
    
    return strM;
}

@end