OC字符串的基本方法及使用说明

Sian · 发表于 2014-3-22 16:54:43

//
// main.m
// NSString-1
//
// Created by yusian on 14-3-22.
// Copyright (c) 2014年小龙虾论坛. All rights reserved.
//
#import <Foundation/Foundation.h>
int main()
{
/**********NSString的几种常用方法*************/
// 1、最常用的创建字符串方法
NSString * str = @"yusian.com";
NSLog(@"str = %@", str);
// 2、不常用的创建字符串方法
NSString * str1 = [NSString stringWithFormat:@"my age is %d", 10];
NSLog(@"str1 = %@",str1);
NSString * str2 = [[NSString alloc] initWithFormat:@"age is %d", 10];
NSLog(@"str2 = %@", str2);
// 3、C语言字符串创建OC字符串对象
NSString * str3 = [NSString stringWithUTF8String:"c to oc"];
NSLog(@"str3 = %@", str3);
// 4、OC字符串创建C语言字符串
const char * cs = [[NSString stringWithFormat:@"oc to c"] UTF8String];
NSLog(@"cs = %s", cs);
// 5、以字符串的方式读取文件内容（注意两个方法的区别）
// 方法一：[NSString stringWithContentsOfFile:<#(NSString *)#> usedEncoding:<#(NSStringEncoding *)#> error:<#(NSError *__autoreleasing *)#>];
// 方法二：[NSString stringWithContentsOfFile:<#(NSString *)#> encoding:<#(NSStringEncoding)#> error:<#(NSError *__autoreleasing *)#>];
NSString * str4 = [NSString stringWithContentsOfFile:@"/Users/yusian/Desktop/1.txt" encoding:NSUTF8StringEncoding error:nil];
// NSUTF8StringEncoding可兼容中文编码
NSLog(@"str4 = %@", str4);
// 6、以字符串的方式读取URL
// > 统一资源定位符（Uniform Resource Locator，缩写为URL）
// > 先定义一个URL,URL可以写"http://abc.com"、"file:///User/yusian/Desktop/..."、"ftp://abc.com"等等；
NSURL *url = [NSURL URLWithString:@"http://baidu.com"];
// 将URL传到NSString的方法当中
NSString * str5 = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:nil];
NSLog(@"str5 = %@", str5);
/**********NSMutableString的几种常用方法***********/
// 1、创建可变字符串的一般方法，可变字符串继承于字符串
NSMutableString * mStr = [NSMutableString stringWithFormat:@"my age is %d", 10];
NSLog(@"mStr = %@", mStr);
// 2、可变字符串可附加内容，这是字符串所不具备的
[mStr appendFormat:@" and height is %dcm.", 173];
NSLog(@"mStr = %@", mStr);
// 3、删除字符串中的特定字符
// 字符串获取子串范围的方法
NSRange range = [mStr rangeOfString:@"my "];
// 通过范围删除字符串中的子串，也可直接写范围，固定范围容易因为字符串的变动而产生误差
[mStr deleteCharactersInRange:range];
NSLog(@"mStr = %@", mStr);
/***********字符串的输出************/
NSString * string = @"yusian.com";
// NSSring及子类都具备该方法
//[string writeToFile:<#(NSString *)#> atomically:<#(BOOL)#> encoding:<#(NSStringEncoding)#> error:<#(NSError *__autoreleasing *)#>]
[string writeToFile:@"/Users/yusian/Desktop/yusian.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];
return 0;
}

复制代码

运行结果：

2014-03-22 16:48:23.076 NSString-1[3340:303] str = yusian.com

2014-03-22 16:48:23.077 NSString-1[3340:303] str1 = my age is 10

2014-03-22 16:48:23.078 NSString-1[3340:303] str2 = age is 10

2014-03-22 16:48:23.078 NSString-1[3340:303] str3 = c to oc

2014-03-22 16:48:23.078 NSString-1[3340:303] cs = oc to c

2014-03-22 16:48:23.079 NSString-1[3340:303] str4 = yusian.com

www.yusian.com

2014-03-22 16:48:23.290 NSString-1[3340:303] str5 = <html>

<meta http-equiv="refresh" content="0;url=http://www.baidu.com/">

</html>

2014-03-22 16:48:23.290 NSString-1[3340:303] mStr = my age is 10

2014-03-22 16:48:23.290 NSString-1[3340:303] mStr = my age is 10 and height is 173cm.

2014-03-22 16:48:23.290 NSString-1[3340:303] mStr = age is 10 and height is 173cm.

Program ended with exit code: 0

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OC字符串的基本方法及使用说明

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