Objective-C中字符串的使用

//创建字符串的方法

NSString *str=@"zhaogang";

NSLog(@"%@",str);

NSString *str1=[NSString
stringWithFormat:@"Your height is %i feet,%i inches",5,11];

NSLog(@"%@",str1);

//返回字符串中字符的个数。

NSLog(@"%lu",[str1
length]);

//字符串的比较①判断两个字符串是否相等②逐个字符进行比较返回enum型数据显示比较结果。

NSString *string1=@"hello 5";

NSString *string2=[NSString
stringWithFormat:@"hello %i",5];

if([string1 isEqualToString:string2])
{

NSLog(@"They are the same!");
}

else
{

NSLog(@"They are different!");
}

NSString *string3=@"abd";

NSString *string4=@"abD";

if([string3 compare:string4]==NSOrderedAscending)
{

NSLog(@"string3<string4");
}

else
if([string3
compare:string4 options:NSCaseInsensitiveSearch|NSNumericSearch]==NSOrderedSame)
{

NSLog(@"string3=string4");
}

else if([string3
compare:string4])
{

NSLog(@"string1>string2");
}

//字符串查找，查找前缀或后缀。

NSString *filename=@"draft-chapter.mov";

if([filename hasPrefix:@"draft"])
{

NSLog(@"draft is prefix");
}

if([filename hasSuffix:@".mov"])
{

NSLog(@".mov is suffix");
}

//查找一个字符内的某处是否包含其他字符串。

NSString *filename1=@"draft-chapter.pages";

NSRange range;
range=[filename1
rangeOfString:@"chapter"];

NSLog(@"%lu,%lu",range.location,range.length);

//可变字符串的创建

NSMutableString *string;
string=[NSMutableString
stringWithCapacity:42];
[string
appendString:@"Hello there "];//将其复制到接收对象的末尾。
[string
appendFormat:@"human %d",39];//将字符串附加在接收字符串的末尾。

NSLog(@"%@",string);

//插入字符串
[string
insertString:@"world"
atIndex:6];

NSLog(@"%@",string);

//替换字符串

NSRange range1=[string
rangeOfString:@"human"];

[string replaceCharactersInRange:range1
withString:@"are"];

NSLog(@"%@",string);

//删除字符串

NSRange range2=[string
rangeOfString:@"Hello"];
[string
deleteCharactersInRange:range2];

NSLog(@"%@",string);