NSString：可以保存字符串逞刷。
創(chuàng)建NSString實例：
- NSString *lament = @"Why me!?";(并沒有明確地發(fā)送消息給NSString類衬以，@"..." 是Objective-C語言中的一個縮寫孕蝉，代表根據(jù)給定的字符串創(chuàng)建一個NSSTring對象怖辆，這種縮寫稱為字面量語法(literal syntax)例朱，該實例稱為NSString的字面量實例(NSString字面量)如输。)
- 創(chuàng)建動態(tài)字符串：NSString *dateString = [NSString stringWithFormat:@"The date is %@",now];(類似于NSLog())
- NSString實例可以保存任意Unicode字符。如果需要插入非ASCII碼字符旭旭，則可以使用\u谎脯，后面加上該字符的十六進制Unicode編碼。如：NSString *slogan = @"I \u2661 New York!";
NSString常用方法：
-
length方法：-(NSUInteger)length （獲取字符串中字符的數(shù)量）持寄。如：
//-(NSUInteger)length NSUInteger charCount = [dateString length]; -
isEqualToString:方法：-(Bool)isEqualToString:(NSString *)other; (查看一個字符串是否和另一個字符串相等)源梭。如：
//-(Bool)isEqualToString:(NSString *)other if([slogan isEqualToString:lament]) { NSLog(@"%@ and %@ are equal",slogan,lament); } -
uppercaseString方法：-(NSString *)uppercaseString;（把一個字符串變成大寫形式）
//-(NSString *)uppercaseString; NSString *angryText = @"That makes me so mad!"; BSString *reallyAngryText = [angryText uppercaseString]; -
查找字符串
//- (NSRange)rangeOfString:(NSString *)searchString
NSString *listOfName = @"...";//名單
NSString *name = @"ward";
NSRange match = [listOfName rangeOfString:name];
if (match.location == NSNotFound) {
NSLog(@"no match found");
} else {
NSLog(@"match found");
}
5. 合并字符串
```js
//- (NSString *)stringByAppendingString:(NSString *)aString;
NSString *one = @"one and ";
NSString *two = @"two";
NSString *methodd = [one stringByAppendingString:two];
NSLog(@"%@",methodd);
