/*NSString 常用方法 */
NSString *str0 = @"第一个字符串";
NSString *str1 = [[NSString
alloc]initWithString:str0];
NSLog(@"str1 = %@", str1);
NSString *str2 = [[NSString
alloc]initWithFormat:@"第二个字符串"];
NSLog(@"第%d个字符串
%@", 2, str2);
[str1
release];
[str2
release];
NSString *name1 =
@"宽宽";
NSString *name2 =
@"王子洁";
NSString *pari = [[NSString
alloc]initWithFormat:@"%@, %@", name1, name2 ];
for (int i =
1; i <= 100; i++) {
@autoreleasepool {
NSString *str3 = [NSString
stringWithFormat:@"第%d个字符串",
i];
NSLog(@"%@", str3);
}
}
// 创建一个新的字符串，可以使用初始化方法和便利构造器。
// 获取字符串长度。
NSLog(@"%lu", [pari
length]);
NSLog(@"%lu", [@"正常的字符串" length]);
// 判断字符串的是否以指定字符串开始或结束。
if ([name2 hasPrefix:@"王"]) {
NSLog(@"王子洁");
}
if ([name2 hasSuffix:@"洁"]) {
NSLog(@"恭喜你答对了");
}
// jpg, png, jpeg, gif, bmp
NSString *fileName =
@"kuankuan.jpg";
if ([fileName hasSuffix:@".jpg"] || [fileName
hasSuffix:@".png"] || [fileName
hasSuffix:@".jpeg"] || [fileName
hasSuffix:@".gif"] || [fileName
hasSuffix:@".bmp"]) {
NSLog(@"%@是一张图片", fileName);
}
else
{
NSLog(@"%@不是一张图片", fileName);
}
//
搜索字符串范围。
NSString *text = @"aBcD_EfGk";
NSRange range = [text
rangeOfString:@"王洁"];
NSLog(@"%lu, %lu", range.location, range.length);
if (range.location ==
NSNotFound) {
NSLog(@"此人已死,有事烧纸");
}
// 字符串截取(获取子字符串)。
//截取c前面的字符串
NSString *text1 = [text
substringToIndex:4];
//截取c后面的字符串
// NSRange range1 = {4, 5};
// NSRange range4 = {0};
// range4.location = 4;
// range4.length = 5;
NSRange range2 = NSMakeRange(4,
5);
NSString *text3 = [text
substringWithRange:range2];
NSString *text2 = [text
substringFromIndex:9];
NSLog(@"%@%@%@", text1, text3, text2);
// 拼接字符串。
NSString *Love = [NSString
stringWithFormat:@"常宽"];
NSLog(@"%@", [[Love
stringByAppendingString:@"回家生猴子"]
stringByAppendingString:@"le"]);
NSLog(@"%@", [Love
stringByAppendingFormat:@"回家生猴子"]);
NSLog(@"%@", [Love
stringByPaddingToLength:7
withString:@"回家生猴子"
startingAtIndex:0]);
// 替换字符串。
NSString *e3 = [NSString
stringWithFormat:@"2B青年"];
NSString *e4 = @"宽宽";
NSLog(@"%@", [e3
stringByReplacingOccurrencesOfString:@"2B"
withString:e4]);
NSRange range3 = {0,
2};
NSString *e5 = [e3
stringByReplacingCharactersInRange:range3
withString:@"小宽宽"];
NSLog(@"%@", e5);
// 字符串比较。
NSLog(@"%ld", [@"A"
compare:@"A"]);// 0代表字符串相等
NSLog(@"%ld", [@"B"
compare:@"A"]);// 1代表降序排列
NSLog(@"%ld", [@"A"
compare:@"B"]);
// -1代表升序排列
NSLog(@"%ld", [@"BA"
compare:@"BB"]);
NSLog(@"%ld", [@"A"
compare:@"C"]);
NSLog(@"~~~~%ld", [@"子杰"
compare:@"宽宽"]);
// 字符串和数值类型转换。
NSString *pi = @"3.1415926";
double p = [pi doubleValue];
NSLog(@"p = %.7f", p);
int a = 5;
NSString *aa = [NSString
stringWithFormat:@"%d", a];
NSLog(@"aa = %@", aa);
//大小写转换操作。
NSString *str5 = @"asdasfsf";
NSString *str6 = @"SDFJS";
//全部转为大写
NSLog(@"%@",[str5
uppercaseString]);
//全部转为小写
NSLog(@"%@",[str6
lowercaseString]);
NSString *ee = @"aBcD_EfGk";
NSRange rang = [ee
rangeOfString:@"EfGk"];
if (rang.location !=
NSNotFound ) {
NSString *bb = [[text
stringByReplacingOccurrencesOfString:@"EfGk"
withString:@"WXYZ"]
lowercaseString];
NSLog(@"%@", bb);
}
NSString *picName =
@"xiao.png";
if ([picName hasSuffix:@".png"]) {
NSString *pic = [picName
stringByReplacingOccurrencesOfString:@".png"
withString:@".jpg"];
NSLog(@"%@", pic);
}
/* NSMutableString
常用方法*/
// 1.创建一个新的字符串
NSMutableString *mStr1 = [NSMutableString
stringWithFormat:@"可变字符串"];
// 2.拼接字符串
[mStr1
appendString:@"可以变长"];
NSLog(@"%@", mStr1);
// mStr1 = [NSMutableString stringWithString:[mStr1 stringByAppendingString:@"很多"]];//
把一个不可变的字符串对象通过用创建对象的方式转变成一个可变的字符串
NSLog(@"%@", mStr1);
// 3.插入字符
[mStr1
insertString:@"的很"
atIndex:8];
NSLog(@"%@", mStr1);
// 4.删除字符
[mStr1 deleteCharactersInRange:NSMakeRange(5,
2)];
NSLog(@"%@", mStr1);