【学习笔记】【Foundation】字符串
NSString
创建字符串:
char *str="string"
NSString* str=@“创建字符串”;
NSString* str=[[NSString alloc]initWithString:@"string"];
NSString* str=[[NSString alloc]initWithFormat:@"age is %d",5];
NSString* str=[[NSString alloc]initWithUTF8String:"abc"];
NSString* str=[[NSString alloc]stringWithString:@"string"];
NSString *str=[NSStringFromRange(range)];
//将数据转化为字符串
NSString* str=[array compenentsJoinedByString:@","];
获取字符串长度
[str length];
获取字符串中的字符或字节:
NSString* s1=[str substringToIndex:10];
NSString* s2=[str substringFromIndex:5];
NSString* s3=[str substringWithRange:NSMakeRange(5,10)];
char c=[str characterAtIndex:1];
获取字符串对应的c风格字符串
const char* cstr=[str UTF8String];
连接字符串:
str=[str stringByAppendingString:@"ios"];
str=[str stringByAppengdingFormat:@"%@is a good book",book]; NSString* book=@"hahaha";
查找字符串内指定的字符或子串:
NSRange pos=[str rangeOfString:@"ios"]; //搜索到就停止搜索,如果需要继续搜索或者从后面搜索可以设置第二个参数;
对字符串进行大小写转换:
str=[str uppercaseString]; //大写
str=[str lowercaseString]; //小写
str=[str capitalizedString]; //首字母大写
比较字符串:
[str isEqualToString: @"ios"];
分割字符串:
NSArray* array=[str componentSeperatedByString:@"."];
类型转换:
NSLog(@“%i”, [@"10" intValue]);
字符串大小比较:
[str compare:s1];
NSMutableString
创建字符串:
NSMutableString* str=[[NSMutableString alloc]initWithCapacity:10];
[str setString:@"sb ni hao"];
追加字符串:
[str appendString:@"hahaha"];
[str appendFormat:@"%i is my age,21"];
替换字符串:
[str replaceCharacterInRange:range withString:@"yoyoyo~"];
NSRange range=[str rangeOfString:@"age"];
删除字符串
[str deleteCharacterInRange:NSMakeRange(location,length)];
插入字符串
[str insertString:@"ni ge sb" atIndex:6];