//建立乙個字串物件
nsstring *str1 = @"www.hello.txt";
nslog(@"%@",str1);
//用格式化字串初始化
int a = 123;
nsstring *str2 =[[nsstring alloc]initwithformat:@"%d %@",a,str1];
nslog(@"%@",str2);
//快速建立乙個字串常量
nsstring *string1 = @"abc";
nsstring *string2 = @"cde";
nslog(@"%@ %@",string1,string2);
//建立乙個格式化的字串 (內存在堆區)
nsstring *string3 = [[nsstring alloc]initwithformat:@"整數: %d",10];
nsstring *string4 = [[nsstring alloc]initwithformat:@"浮點數: %f",10.0];
nslog(@"%@ %@",string3,string4);
//字串比較
nsstring *string5 = [nsstring stringwithformat:@"123"];
nsstring *string6 = [nsstring stringwithformat:@"124"];
//測試內容是否相等
//方法一
if ([string5 isequaltostring:string6]) else
//方法二
//bool : yes(1) no(0)
bool rst = [string5 compare:string6];
nslog(@"%d",rst);
//方法三
//不區分大小寫比較字串大小
nsstring *astring = @"abc";
nsstring *otherstring = @"abc";
nscomparisonresult rst3 = [astring compare:otherstring];
nslog(@"%ld",rst3);
//測試內容是否指向同乙個物件
if (string5 == string6) else
//求字串長度
nslog(@"%ld",[string6 length]);
//擷取字串中的字元
nslog(@"%c",[string6 characteratindex:2]);
//字串轉換
nsstring *string7 = @"hello world";
nslog(@"%@",[string7 uppercasestring]);
nslog(@"%@",[string7 lowercasestring]);
nslog(@"%@",[string7 capitalizedstring]);
//轉換成基本資料型別
nsstring *string8 = @"3.14";
float pi = [string8 floatvalue];
nslog(@"%f",pi);
//將oc字元轉化為c的字元
const char *p = [string8 utf8string];
nslog(@"%c",*p);
//將字串轉換為陣列
nsstring *string9 = @"abc bcd xyz";
nsarray *array = [string9 componentsseparatedbystring:@" "];
nslog(@"array: %@",array);
//擷取字串
nsstring *string10 = @"abcdefg";
nsstring *substring1 = [string10 substringtoindex:2];
nslog(@"%@",substring1);
nsstring *substring2 = [string10 substringfromindex:2];
nslog(@"%@",substring2);
//通過查詢擷取
nsrange range = ;
range.location = 4;
range.length = 2;
//在range指定範圍內抽取
nsstring *substring3 = [string10 substringwithrange:range];
nslog(@"%@",substring3);
//nsmakerange
nsstring *substring4 = [string10 substringwithrange:nsmakerange(4, 3)];
nslog(@"%@",substring4);
//字串拼接
nsstring *string11 = @"abc";
nsstring *string12 = @"xyz";
//查詢字串物件
nsstring *link = @"abcdetarget=_blankxyz";
//查詢子串,找不到返回
nsrange range1 = [link rangeofstring:@"target=_blank"];
if (range1.location != nsnotfound)
//判斷字串是否以指定字串開頭
bool rst5 = [string1 hasprefix:@"www"];
nslog(@"%d",rst5);
//判斷字串是否以指定字串結尾
bool rst6 = [string1 hassuffix:@".txt"];
nslog(@"%d",rst6);
//可變字串物件:nsmutablestring繼承至string
nsmutablestring *mutablestring1 = [[nsmutablestring alloc]initwithformat:@"abc"];
nslog(@"%@",mutablestring1);
//對可變字串賦值
[mutablestring1 setstring:@"qianfeng"];
nslog(@"%@",mutablestring1);
//插入乙個字串,在指定下標(不要越界)位置插入nsstring型別字元
[mutablestring1 insertstring:@"...xyz" atindex:3];
nslog(@"%@",mutablestring1);
//在字串末尾追加字串
nslog(@"%@",mutablestring1);
//替換
nsrange range2=;
[mutablestring1 replacecharactersinrange:range2 withstring:@"efg"];
nslog(@"%@",mutablestring1);
//刪除
[mutablestring1 deletecharactersinrange:range2];
nslog(@"%@",mutablestring1);
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NSString 常用方法
建立乙個新字串並將其設定為 path 指定的檔案的內容,使用字元編碼enc,在error上返回錯誤 id stringwithcontentsofurl nsurl url encoding nsstringencoding enc error nserror error 建立乙個新字串並將其設定為...