OC 字符串操作整理

//
//  main.m
//  StringMK
//
//  Created by LXC on 16/1/7.
//  Copyright © 2016年 LXC. All rights reserved.
//  2016年01月07日23:51:29
//

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        NSLog(@"Hello, World!");
        
        //C
        char *s = "Hello C";
        //OC
        NSString *str = @"Hello";
        //C --> OC
        NSString *str1 = [NSString stringWithUTF8String:s];
        NSLog(@"str1 = %@",str1);
        //OC --> C
        NSLog(@"str2 = %s",[str UTF8String]);
        
        //创建字符串
        NSString *str3 = @"IOS";//不需要自己释放内存
        NSString *str4 = [[NSString alloc] init];//先分配内存 在初始化
        str4 = @"IOS";
        
        //格式化字符串
        int a = 10;
        int b = 20;
        
        NSString *str5 = [NSString stringWithFormat:@"a = %d,b = %d",a,b];
        NSLog(@"str5 = %@",str5);
        
        //拼接字符串
        NSString *str6 = [str5 stringByAppendingString:str3];
        NSLog(@"str6 = %@",str6);
        
        //大小写转换
        NSString *str7 = @"ASDASDA";
        NSString *str8 =  [str7 lowercaseString];
        NSLog(@"str8 = %@",str8);
        NSString *str9 = [str7 uppercaseString];
        NSLog(@"str9 = %@",str9);
        
        //前缀和后缀的判断
        NSString *str10 = @"www.liuxincheng.win";
        BOOL hasPrFix  = [str10 hasPrefix:@"www."];
        if (hasPrFix) {
            NSLog(@"YES");
        }else{
            NSLog(@"NO");
        }
        BOOL hasSuffix  = [str10 hasSuffix:@".win"];
        if (hasSuffix) {
            NSLog(@"YES");
        }else{
            NSLog(@"NO");
        }

        //判断两个字符川是否相同
        
        NSString *str11 = @"LXC";
        NSString *str12 = @" LXC";
        if ([str11 isEqualToString:str12]) {
            NSLog(@"SAME");
        }else{
            NSLog(@"diff");
        }
        
        //比较字符串 NSComparisonResult
        
        //分割字符串
        //按照指定字符分割字符串
        NSString *str13 = @"a,b,c,d,e,f";
        NSArray *strarray = [str13 componentsSeparatedByString:@","];
        for (NSString *str in strarray) {
            NSLog(@"STR = %@",str);
        }
        
        //按照范围切割字符串
        NSRange range = NSMakeRange(1,5);
        NSString *str14 = [str13 substringWithRange:range];
        NSLog(@"STR14 = %@",str14);
        
        //从某一位开始截取
        NSString *str15 = [str13 substringFromIndex:2];
        NSLog(@"STR15 = %@",str15);
        //截取到某一位
        NSString *str16 = [str13 substringToIndex:2];
        NSLog(@"STR16 = %@",str16);
        //拆分到每一个字符
        for(int i=0;i<[str13 length];i++){
            NSLog(@"STRCHAR =  %c",[str13 characterAtIndex:i]);
        }
        
        
        //查找
        NSString *str17 = @"ad ad fe ef cv gh";
        NSRange range1 = [str17 rangeOfString:@"cv"];
        NSLog(@"range.location : %ld range1.length : %ld",range1.location,range1.length);
        
        //替换
        NSString *str18 = @"Hello ios ,hello lxc";
        //替换某一个范围的内容
        NSString *str19 = [str18 stringByReplacingCharactersInRange:NSMakeRange(0, 5) withString:@"LXC"];
        NSLog(@"%@",str19);
        
        //用指定字符串替换原字符串中的字串
        /*
         第一个参数是被替换的内容
         第二个参数是要替换的内容
         */
        NSString *str20 = [str18 stringByReplacingOccurrencesOfString:@"Hello" withString:@"ni hao"];
        NSLog(@"%@",str20);
        
        //读取文件 文件来源
        //本地文件 网络文件
        
        NSString *str21 = @"www.liuxincheng.win";
        //网络路径
        NSURL *httpURL = [NSURL URLWithString:str21];
        //本地路径
        NSString *str22 = @"/Users/lxc/Desktop/test.txt";
        NSURL *fileURL = [NSURL fileURLWithPath:str22];
        //读取网络文件
        NSString *httpstr = [NSString stringWithContentsOfURL:httpURL encoding:NSUTF8StringEncoding error:nil];
        //读取本地文件
        NSString *filestr = [NSString stringWithContentsOfFile:str22 encoding:NSUTF8StringEncoding error:nil];
        
        NSLog(@"HTTP %@ FILE %@",httpstr,filestr);
        
        //写入文件
        NSString *str23 = @"jinzhuanch";
        BOOL isok =  [str23 writeToFile:@"/Users/lxc/Desktop/demo.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];
        
        if (isok) {
            NSLog(@"OK");
        }else{
            NSLog(@"NO");
        }
        //可变字符串是字符串的子类
        NSMutableString *str24 = [[NSMutableString alloc] initWithCapacity:10];
        [str24 setString:@"kun"];
        
        //追加字符串
        [str24 appendFormat:@" siwole"];
        NSLog(@"str24 = %@",str24);
        int c = 10;
        [str24 appendFormat:@" ---%i",c];
        NSLog(@"str25 ---- %@",str24);
        
        //替换字符串
        NSRange ranges = [str24 rangeOfString:@"siwole"];
        [str24 replaceCharactersInRange:ranges withString:@"sleep"];
        NSLog(@"str26 --- %@",str24);
        
        //插入字符串
        [str24 insertString:@"OMG" atIndex:2];
        NSLog(@"str27 == %@",str24);
        
        //删除字符串
        NSRange rangess = [str24 rangeOfString:@"OMG"];
        [str24 deleteCharactersInRange:rangess];
        NSLog(@"str28 ==== %@",str24);
    }
    return 0;
}