********************************总结字符串的用法**********************************
C转OC
方法:stringWithUTF8String
OC转C
方法:UTF8String
字符串的创建
方法:alloc或者语法糖
格式化成字符串
方法:stringWithFormat
字符串比较大小
方法:compare返回值有NSComparasonReslut(枚举类型)
判断字符串相等
方法:isEqualToString
判断前缀
方法:hasPrefix
判断后缀
方法:hasSuffix
判断是否包含
方法:containsString
查找字符串的位置
方法:rangeOfString
字符串大写
方法:uppercaseString
字符串小写
方法:lowercaseString
字符串首字母大写
方法:capitalizedString
字符串的拼接
方法:stringByappendingString
字符串的分割(用数组去接收)
方法:componentsSeparatedByString
字符串的截取
第一种:通过下标截取单个字符
方法:characterAtIndex
第二种:按照范围截取
方法:substringWithRange
第三种:从头开始截取到某一位
方法:substringToIndex
第四种:从某位开始截取到最后
方法:substringFromIndex
字符串的替换
方法:第一种:按照范围替换
stringByReplacingCharactersInRange
第二种:按照字符替换
方法:stringByReplacingOccurrencesOfString
**************************************演练********************************************
//OC和C字符串的转换
//C转换OC(stringWithUTF8String)
char* strC ="hello";
NSString * strOC = [NSString stringWithUTF8String:strC];
NSLog(@"%@", strOC);
//OC转换C(UTF8String)
NSString * strOC1 =@"hello";
char* strC1 = [strOC1 UTF8String];
NSLog(@"%s", strC1);
//创建字符串的两种方法:
//第一种:(alloc)
NSString * strCreat = [[NSString alloc] init];
strCreat =@"create string";
//第二种:(语法糖)
NSString * strCreat2 =@"creat string";
//格式化字符串(stringWithFormat)
inta =10;
NSString * strFormat = [NSString stringWithFormat:@"%d", a];
//字符串的拼接(stringByAppendingString)
NSString * strAppending1 =@"hello";
NSString * strAppending2 =@"world";
NSString * strAppending = [strAppending1 stringByAppendingString:strAppending2];
NSLog(@"%@", strAppending);
//字符串的比较(compare枚举类型,同时我们要使用NSComparisonResult来接这个结果)
NSString * strCompare1 =@" a, b, c, d, e";
NSString * strCompare2 =@" a, e, f, g, h";
NSComparisonResult strCompare = [strCompare1 compare:strCompare2];
if(strCompare ==0) {
NSLog(@"相等");
}elseif(strCompare >0){
NSLog(@"降序");
}else{
NSLog(@"升序");
}
//字符串的分割(componentSeparatedByString,同时用数组去接收)
NSString * strComponent =@" a, b, c, d, e, f, g";
NSArray * array = [strComponent componentsSeparatedByString:@","];
NSLog(@"%@", array);
//字符串通过Index取字符(characterAtIndex)
NSString * string =@"hello world";
charstrChar = [string characterAtIndex:6];
NSLog(@"%c",strChar);
//字符串的截取
//按照范围截取字符串(substringWithRange,范围:NSRange)
NSString * strSub =@"hello world objectC";
NSRange range = NSMakeRange(6,5);//我们取得就是world
NSString * strSubReslut = [strSub substringWithRange:range];
NSLog(@"%@", strSubReslut);
//从开头截取到某一位(substringToIndex,从0开始,index所填的位置不包括)
NSString * strSubstringToIndex = [strSub substringToIndex:5];
NSLog(@"%@", strSubstringToIndex);
//从某一位开始截取到最后(substringFromIndex,从0开始,index所填的位置包括)
NSString * strSubstringFromIndex = [strSub substringFromIndex:6];
NSLog(@"%@", strSubstringFromIndex);
//字符串的查找(rangeOfString通过NSRange接收,最后得出的就是位置)
NSString * string1 =@"ab cd ef gh";
NSRange range1 = [string1 rangeOfString:@"ab"];
NSLog(@"location:%lu, length:%ld", (unsignedlong)range1.location, range1.length);
//字符串的替换
//第一种:按照范围进行替换(stringByReplecingCharactersInrange)
NSString * string3 =@"hello iOS, hello world";
NSRange range2 = NSMakeRange(0,5);
NSString * strRaplecingChar = [string3 stringByReplacingCharactersInRange:range2 withString:@"world"];
NSLog(@"%@", strRaplecingChar);
//第二种:通过字符去替换字符(stringByReplacingOccurrencesOfString)
NSString * strRaplecingOccurrences = [string3 stringByReplacingOccurrencesOfString:@"hello"withString:@"object"];
NSLog(@"%@", strRaplecingOccurrences);
//判断字符串是否包含(containsString)
NSString * string4 =@"hello world iOS";
BOOLcontainsString = [string4 containsString:@"iOS"];
NSLog(@"%d", containsString);
if(containsString ==0) {
NSLog(@"包含");
}else{
NSLog(@"不包含");
}
//判断前缀和后缀
NSString * string5 =@"www.baidu.com";
//前缀(hasPrefix)
BOOLhasPrefix = [string5 hasPrefix:@"www"];
if(hasPrefix ==1) {
NSLog(@"有对应的前缀");
}else{
NSLog(@"没有对应的前缀");
}
//后缀(hasSuffix)
BOOLhasSuffix = [string5 hasSuffix:@"com"];
if(hasSuffix ==1) {
NSLog(@"有对应的后缀");
}else{
NSLog(@"没有对应的后缀");
}
//判断两个字符串是否相同
NSString * strEqual1 =@"hello";
NSString * strEqual2 =@"hello";
if([strEqual1 isEqualToString:strEqual2] ==1) {
NSLog(@"相等");
}else{
NSLog(@"不相等");
}
//字符串大小写转换
//小写(lowercaseString)
NSString * string6 =@"ABCDEF";
NSString * strLowercase = [string6 lowercaseString];
NSLog(@"%@", strLowercase);
//大写(uppercaseString)
NSString * string7 =@"abcdef";
NSString * strUppercase = [string7 uppercaseString];
NSLog(@"%@", strUppercase);
//首字母大写(capitalizedString)
NSString * string8 =@"abcdef";
NSString * strCapitalize = [string8 capitalizedString];
NSLog(@"%@", strCapitalize);