3、字符串比较
NSString *str7 = @"hello000";
NSString *str8 = [NSString stringWithString:str7];
NSString *str9 = [NSString stringWithFormat:@"HE%@",@"llo00000"]; NSLog(@"str7 >>>>> %p", str7);
NSLog(@"str8 >>>>> %p", str8);
NSLog(@"str9 >>>>> %p", str9); // str7和str9本质是两个指针，所以直接用==比较值
if (str7 == str9) {
NSLog(@"相等");
} else {
NSLog(@"不相等");
} // 比较字符串内容是否一样
if ([str7 isEqualToString:str9]) {
NSLog(@"相等");
} else {
NSLog(@"不相等");
} NSString *str12 = @""; NSString *str13 = @""; NSComparisonResult result1 = [str12 compare:str13 options:NSCaseInsensitiveSearch range:NSMakeRange(,)]; //options 选项 range 类别 NSLog(@"result1 >>> %ld", result1);
4、字符串拼接
NSString *str14 = @"hello";
NSString *str15 = [str14 stringByAppendingString:@"lisi"];//append 附加，添加
NSString *str16 = [@"/Users/nidediannaomingzi" stringByAppendingPathComponent:@"Desktop"];5.字符串查找
NSString *str17 = @"nice nice nice";
if ([str17 containsString:@"nnnn"]) {
NSLog(@"jin lai le");
}//contains 包含，容纳 NSString *str18 = @"410000xxxxxxxxxx";
if ([str18 hasPrefix:@""]) {
NSLog(@"shi de ");
}// hasPrefix:方法的功能是判断创建的字符串内容是否以某个前缀开始 NSString *str19 = @"icon.exe";
if ([str19 hasSuffix:@"png"] || [str19 hasSuffix:@"jpg"]) {
NSLog(@"合法头像");
}//hasSuffix:方法的功能是判断创建的字符串内容是否以某个后缀开始 NSString *str20 = @"~/Desktop/test.h"; NSLog(@"pathExtension >>> %@", [str20 pathExtension]);// 文件扩展名 Extension 扩展，扩大 NSLog(@"absolute path >>> %@", [str20 stringByExpandingTildeInPath]); //Expand 展开 tilde波浪号 NSLog(@"absolute path >>> %@", [[str20 stringByExpandingTildeInPath] stringByAbbreviatingWithTildeInPath]); // 合闭波 浪号 abbreviate缩略 缩短
6、字符串截取
NSString *str21 = @"hello, yangyang";
NSLog(@"subString >>> %@", [str21 substringFromIndex:]);//sub 词根是‘子’ 从第六个字符截取
NSLog(@"subString >>> %@", [str21 substringToIndex:]); // 截取六个字符
NSLog(@"subString >>> %@", [str21 substringWithRange:NSMakeRange(, )]); //字定义截取范围
//截取？之后的
NSRange sizeRange= [presaleGuideURL rangeOfString:@"?"];
NSString *whatStr1 = [presaleGuideURL substringFromIndex:sizeRange.location+];
NSLog(@"-->%@",whatStr1);//model=product&action=guidelines&goods_id=138206 //截取到？
NSString *whatStr2 = [presaleGuideURL substringToIndex:sizeRange.location];
NSLog(@"-->%@",whatStr2);//http://rwandroid.shetest.cn/index.php //从？之后截取5位
NSRange myRange = [presaleGuideURL rangeOfString:@"?"];
myRange.length = ;
NSString *whatStr3 = [presaleGuideURL substringWithRange:myRange];//?mode
NSLog(@"-->%@",whatStr3);
7、字符串大小写转换
NSString *enString = @"In our life, some love was doomed to no end, it is only responsible for the meeting.";
NSLog(@"全大写------>%@", [enString uppercaseString]);
NSLog(@"全小写------>%@", [enString lowercaseString]);
NSLog(@"首字母大写--->%@", [enString capitalizedString]); 全大写------>IN OUR LIFE, SOME LOVE WAS DOOMED TO NO END, IT IS ONLY RESPONSIBLE FOR THE MEETING.
全小写------>in our life, some love was doomed to no end, it is only responsible for the meeting.
首字母大写--->In Our Life, Some Love Was Doomed To No End, It Is Only Responsible For The Meeting. // 字母变换大小写时，中文字符被忽略，不会报错
NSString *enChString = @"ps: 在我们一生中，有的爱情本来就注定没有结局，它只负责相遇。";
NSLog(@"全大写------>%@", [enChString uppercaseString]);
NSLog(@"全小写------>%@", [enChString lowercaseString]);
NSLog(@"首字母大写--->%@", [enChString capitalizedString]); 全大写------>PS: 在我们一生中，有的爱情本来就注定没有结局，它只负责相遇。
全小写------>ps: 在我们一生中，有的爱情本来就注定没有结局，它只负责相遇。
首字母大写--->Ps: 在我们一生中，有的爱情本来就注定没有结局，它只负责相遇。
/*********可变字符串*********/
//NSMutableString *mstr = [NSMutableString stringWithCapacity:50];// Capacity容量
//NSMutableString *mstr = [NSMutableString stringWithString:@"haha"];
NSMutableString *mstr = [NSMutableString stringWithFormat:@"haha-%@-", @"xiaosan"];1、追加
[mstr appendString:@"zhang"];
[mstr appendString:@"san"];2.删除
[mstr deleteCharactersInRange:NSMakeRange(, )];
3.插入
[mstr insertString:@"haha" atIndex:];
4.替换
[mstr replaceCharactersInRange:NSMakeRange(, ) withString:@"woshitihuan"];//从第五个字符开始用teacher替换4个字符
5.格式化追加
[mstr appendFormat:@"-%@", @"stage1"];
6、字符串赋值
str31 = str30;
[str31 appendString: @" 和字符串2"];