Object-c------Foundation中的结构体和字符串

main.m

//
//  main.m
//  Foundation
//
//  Created by zhaogang on 16/5/6.
//  Copyright ? 2016年 zhaogang. All rights reserved.
//

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {

    NSError *error = nil;
    NSString *path = @"/Users/zzzigo/Desktop/test.txt";
    NSString *str = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:&error];
    NSLog(@"%@", str);

    //同样url也可以用，同之前的写入
    //[NSString alloc] initWithContentsOfURL:<#(nonnull NSURL *)#> encoding:<#(NSStringEncoding)#> error:<#(NSError * _Nullable __autoreleasing * _Nullable)#>

    return 0;
}

void export()
{
    NSString *str = @"jack";
    NSString *path = @"/Users/zzzigo/Desktop/test.txt";
    NSError *error = nil;
    //写入文件
    //[str writeToFile:path atomically:YES encoding:NSUTF8StringEncoding error:&error];

    //也是写入一个文件
    //NSURL *url = [NSURL URLWithString:@"file:///Users/zzzigo/Desktop/test.txt"];
    NSURL *url = [NSURL fileURLWithPath:@"/Users/zzzigo/Desktop/test.txt"];
    [str writeToURL:url atomically:YES encoding:NSUTF8StringEncoding error:&error];

    if(error)
        NSLog(@"write fail! error = %@ !" , [error localizedDescription]);//error

    else
        NSLog(@"write sucess");
}

void mutableStr()
{
    //NSString是不可变字符串
    //可变字符
    NSMutableString *str = [[NSMutableString alloc] initWithCapacity:0];

    [str appendFormat:@"123"];

    NSString *str1 = @"123";
    //追加一个字符串
    NSString *str2 = [str1 stringByAppendingString:@"aaa"];
    //找到一个字符串的范围
    NSRange range3 = [str1 rangeOfString:@"3"];
    //用字符串的范围删除这个字符串
    [str deleteCharactersInRange:range3];
    //插入字符串
    [str insertString:@"aaa" atIndex:0];

    //替换
    [str replaceOccurrencesOfString:@"3" withString:@"" options:NSLiteralSearch range:NSMakeRange(0, str.length) ];
    NSLog(@"%@",str);
}

void stringis()
{
    NSString *str = @"qq=444381246&pwd=jiuge1";
    //检测是否以qq＝开头
    [str hasPrefix:@"qq="];
    //检测是否以jiuge1结尾
    [str hasSuffix:@"jiuge1"];
}

void test()
{
    //这两个是等价的
    NSString *str = @"jack";
    NSString *str1 = [[NSString alloc] initWithString:@"jack"];

    //类似于c里面的sprintf
    NSString *str2 = [[NSString alloc] initWithFormat:@"%d, %f",10 , 1.f];

    // http://im.qq.com?qq=123&pwd=123
    NSString *qqURL = @"http://im.qq.com?qq=444381246&pwd=jiuge1";
    //取得qq在url里面的范围
    NSRange qqRange = [qqURL rangeOfString:@"qq="];

    //或者 qqRange.location == NSNotFound
    if(qqRange.length)
        NSLog(@"len = %zd, loc = %zd",qqRange.length, qqRange.location);
    else
        NSLog(@"nothing!");

    NSRange pwdRange = [qqURL rangeOfString:@"&pwd="];
    //取出账号的范围
    NSRange range = NSMakeRange(qqRange.location + qqRange.length, pwdRange.location - (qqRange.length + qqRange.location));

    //账号
    //根据range切割字符串
    NSString *qqId = [qqURL substringWithRange: range];
    NSLog(@"qqId = %@", qqId);

    //密码
    //根据index切割字符串
    NSString *qqPwd = [qqURL substringFromIndex:pwdRange.location + pwdRange.length];
    NSLog(@"qqPwd = %@", qqPwd);

    //1.将字符串变为大小写字母，
    NSString *str3 = nil;
    //str =[qqPwd lowercaseString];
    str = [qqPwd uppercaseString];

    //2.两个字符串比较
    if([str isEqualToString:@"JIUGE1"])
        NSLog(@"pwd is right!");
    else
        NSLog(@"pwd is wrong!");
}

void range()
{
    //表示一个范围，比如@"12345"
    NSRange range = {1, 2}; //表示字符串里的 2 3
    NSRange range2 = {.location = 1, .length = 3};//表示字符串里的 2 3 4

    NSRange range3 = NSMakeRange(1, 3); //表示字符串里的 2 3 4
}

void point()
{
    //NSPoint CGPoint 表示平面里面的一个点

    CGPoint pt = {1, 2};
    CGPoint pt1 = {.x = 1, .y = 2};

    CGPoint pt2 = NSMakePoint(1, 3);
}

void size()
{
    //大小，有宽和高
    //NSSize CGSize
    CGSize size = NSMakeSize(10, 100);

    //前两个参数表示坐标
    CGRect rect = NSMakeRect(0, 0, 100, 100);
}