IOS 学习笔记 2015-03-24 OC-API-不可变字符串

大部分是模仿
//
//  main.m
//  OC-API-不可变字符串
//
//  Created by wangtouwang on 15/3/25.
//  Copyright (c) 2015年 wangtouwang. All rights reserved.
//

#import <Foundation/Foundation.h>

//初始化
void testInit(){
    //创建C 字符串对象
    char str0 ="C String";
    //创建字符串对象 无需释放内存
    NSString *str1 = @"MAIKE";
    //创建字符串对象 需要释放内存
    NSString *str2 = [[NSString alloc] initWithString : @"JACK" ];
    NSString *str3 = [[NSString alloc] initWithFormat:@"LUCY %i",12];
    NSString *str4 = [[NSString alloc] initWithUTF8String:"C String"];
    
    //以上方法都有对于的静态方法,也无需释放内存
    str2 = [NSString stringWithString:@"STATIC JACK"];
    str3 = [NSString stringWithFormat:@"STATIC LUCY %i",12];
    str4 = [NSString stringWithUTF8String:"C String"];
}


int main(int argc, const char * argv[]) {
    @autoreleasepool {
      //转换成大写
        NSLog(@"zhangjianhua 转换成 大写 %@",[@"zhangjianhua" uppercaseString]);
     //转换成小写
        NSLog(@"ZHANGJIANHUA 转换成 小写 %@",[@"ZHANGJIANHUA" lowercaseString]);
     //首字母大写
        NSLog(@"zhangjianhua 转换成 小写 %@",[@"zhangjianhua" capitalizedString]);
      //比较字符串内容
        NSLog(@" ABC isEqualToString Abc to result= %i",[@"ABC" isEqualToString:@"Abc"]);
        //比较字符串内容 忽略大小写
        NSComparisonResult result2= [@"abc" compare:@"aBc"];//如果是[@"abc" caseInsensitiveCompare:@"aBc"]则忽略大小写比较
        if(result2==NSOrderedAscending){
            NSLog(@"left<right.");
        }else if(result2==NSOrderedDescending){
            NSLog(@"left>right.");
        }else if(result2==NSOrderedSame){
            NSLog(@"left=right.");
        }
        //查询指定字符串在前缀什么位置
        NSLog(@" ABCDEFJ BY CD in location %i",[@"ABCDEFJ" hasPrefix:@"CD"]);
        //查询指定字符串在后缀什么位置
        NSLog(@" ABCDEFJ BY FJ in location %i",[@"ABCDEFJ" hasSuffix:@"F"]);
        //查询指定字符串在什么位置和长度
        NSLog(@" ABCDEFJ BY CD in location %@", NSStringFromRange([@"ABCDEFJ" rangeOfString:@"CD"]));
        //截取指定字符串位置 根据CGRange对象
        NSLog(@"JAVA Subetring TO Result  %@",[@"ABCDEFG" substringWithRange:NSMakeRange(2, 2)]);
        //截取指定字符串对象 根据下标 从0到了该位置就停止
        NSLog(@"SubString String By Index %@",[@"ABCDEFG" substringToIndex:2]);
        //截取指定字符串对象 根据下标 从位置到结尾停止
        NSLog(@"SubString String By Index %@",[@"ABCDEFG" substringFromIndex:2]);
        
        //字符串分割
        NSString *str9 = @"MY NAME IS WP,AGE=28";
        NSArray *array = [str9 componentsSeparatedByString:@" "];
        NSLog(@"%@",array);
        
        //内型转换
        //转换成int
        NSLog(@"%i",[@"13" intValue]);
        //转换成C语音字符串
        const char *s=[@"abc" UTF8String];//转换为C语言字符串
        NSLog(@"%s",s);
      
         NSLog(@"%c",[@"abc" characterAtIndex:0]);//取出制定位置的字符
        
    }
    return 0;
}