day03-03-NSString和NSMutableString

Objective-c

//  main.m
//  day03-03-NSString和NSMutableString
//
//  Created by Aaron on 15/7/3.
//  Copyright (c) 2015年 Aaron. All rights reserved.
//
#import <Foundation/Foundation.h>
//搜索字符串
#if 0
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSString *str = @"abbcdeahbcfg";
        /*
         typedef struct _NSRange {
         NSUInteger location;  索引
         NSUInteger length;    长度
         } NSRange;
         */
        //rangeOfString:  搜索子字符串
        //返回一个range
        //注意: 返回的是第一次出现的范围
        NSRange range = [str rangeOfString:@"abc"];
        //判断是否搜索到的方法:
        //一:直接通过长度
        if(range.length != 0)
        {
            NSLog(@"搜索到");
        }
        else
        {
            NSLog(@"%ld %ld",range.location,range.length);
        }
        //二:利用位置
        if(range.location == NSNotFound)
        {
            NSLog(@"没有搜索到");
        }
        else
        {
            NSLog(@"搜索到了");
        }
        NSString *str2 = @"abcdefg";
        NSString *str3 = @"cde";
        NSRange range1 = {1,3};
        NSComparisonResult state = [str2 compare:str3 options:NSLiteralSearch range:range1];
        NSLog(@"%ld",state);
    }
    return 0;
}
#endif
#if 0
int main()
{
    //抽取子字符串
    NSString *str = @"hello world";
    //NSRange range = {2,2};
    //按照范围来抽取子字符串
    //- (NSString *)substringWithRange:(NSRange)range;
    //str = [str substringWithRange:NSMakeRange(2, 2)];
    //NSLog(@"%@",str);
    //从指定的索引开始抽取子字符串
    //注意: 包含索引对应的字符
    //str = [str substringFromIndex:2];
    //NSLog(@"%@",str);
    //从头开始抽取到指定的索引为止
    //注意: 不包含索引对应的字符
    str = [str substringToIndex:2];
    NSLog(@"%@",str);
}
#endif
/*
 When I was young, I'd listen to the radio, waiting for my favorite songs. 从was提取到radio;
 */
#if 0
int main()
{
    NSString *str = @"When I was young, I'd listen to the radio, waiting for my favorite songs.";
    //1.确定用range来抽取
    //2.location是was里面w出现的位置
    NSRange range1 = [str rangeOfString:@"was"];
    //3.因为location可以代表前面有多少个字节
    NSRange range2 = [str rangeOfString:@"radio"];
    NSString *subStr = [str substringWithRange:NSMakeRange(range1.location, range2.location-range1.location+range2.length)];
    NSLog(@"%@",subStr);
}
#endif
/*
 查找子字符串出现的次数
 abcdefefefd
 ef
 */
#if 0
int main()
{
    NSString *str = @"abcdefefefd";
    NSRange range = {0,0};
    NSInteger times = 0;
    while(1)
    {
        str = [str substringFromIndex:range.location+range.length];
        range = [str rangeOfString:@"ef"];
        if(range.location == NSNotFound)
        {
            break;
        }
        else
        {
            times++;
        }
    }
    NSLog(@"出现了%ld次",times);
}
#endif
#if 0
int main()
{
    NSString *str = @"sgddshjagdhasgdh";
    //可以从后往前搜索
    NSRange range = [str rangeOfString:@"sgd" options:NSBackwardsSearch];
    //NSLog(@"%@",NSStringFromRange(range));
    //可以指定范围搜索
    //注意:返回的location是针对原字符串的索引
    range = [str rangeOfString:@"sgd" options:NSLiteralSearch range:NSMakeRange(1, 15)];
    // FOUNDATION_EXPORT NSString *NSStringFromRange(NSRange range);
        //这里的NSStringFromRange(range) 是一个字符串，也就是单纯的把range按照字符串的格式输出 可以输出range（结构体）的形式
    NSLog(@"%@",NSStringFromRange(range));
}
#endif
#if 0
int main()
{
    NSString *str1 = @"hello world";
    //获取字符串的长度
    NSInteger length = [str1 length];
    NSLog(@"%ld",length);
    //- (unichar)characterAtIndex:(NSUInteger)index;
    //获取指定索引对应的字符
    //unichar 是转成unicode码之后的两个字节的数据
    NSLog(@"%C",[str1 characterAtIndex:0]);
    //将字符串转成大写
    str1 = [str1 uppercaseString];
    NSLog(@"%@",str1);
    //将字符串转成小写
    str1 = [str1 lowercaseString];
    NSLog(@"%@",str1);
    //将单词首字母转成大写
    str1 = [str1 capitalizedString];
    NSLog(@"%@",str1);
    //@"www.baidu.com"
    NSString *str2 = @"www.baidu.com";
    BOOL rec = [str2 hasPrefix:@"www"];
    NSLog(@"%@",rec?@"有前缀":@"无前缀");
    //作业:自己实现判断是否有前缀,后缀
    rec = [str2 hasSuffix:@".com"];
    NSLog(@"%@",rec?@"有后缀":@"无后缀");
    // /users/Aaron/desktop/test1.txt
    NSString *str3 = @"1.23";
    //将字符串转成基本类型的数据
    float temp = [str3 floatValue];
    NSLog(@"%.2f",temp);
    //注意:转换的时候,遇到不是数字的字符就停止
    NSString *str4 = @"a1001";
    int t = [str4 intValue];
    NSLog(@"%d",t);
    const char *s = [str4 UTF8String];
    NSLog(@"%s",s);
}
#endif
int main()
{
    //可变字符串
    NSMutableString *str1 = [[NSMutableString alloc] init];
    //init对于可变字符串是有意义的
    NSMutableString *str2 = [NSMutableString string];
    NSMutableString *str3 = [NSMutableString stringWithString:@"hello"];
    NSLog(@"%@",str3);
    NSString *str4 = [[NSString alloc] initWithString:str3];
    //可变字符串仅仅是在不可变的基础上增加了  增删改几种方法
    //增
    //追加字符串
    [str3 appendString:@"xxx"];
    NSLog(@"%@",str3);
    //追加格式
    [str3 appendFormat:@"teacherName:%@",@"xiaoxin"];
    NSLog(@"%@",str3);
    //插入
    [str3 insertString:@"..." atIndex:0];
    NSLog(@"%@",str3);
    //删除
    //删除指定范围内的字符
    [str3 deleteCharactersInRange:NSMakeRange(0, 8)];
    NSLog(@"%@",str3);
    //修改
    [str3 replaceCharactersInRange:NSMakeRange(3, 7) withString:@""];
    NSLog(@"%@",str3);
    //直接设置字符串内容
    [str3 setString:@""];
    NSLog(@"--%@",str3);
}