//
// main.m
// OC4_NSString操作
//
// Created by zhangxueming on 15/6/10.
// Copyright (c) 2015年 zhangxueming. All rights reserved.
//
#import <Foundation/Foundation.h>
//NSString
int main(
int argc,
const char *
argv[]) {
@autoreleasepool {
NSString *str1 =
@"hello world 千锋";
//求字符串长度
NSUInteger len =
[str1 length];
NSLog(@"len = %li", len);
//获取字符串指定位置的字符
unichar ch = [str1 characterAtIndex:
13];
NSLog(@"ch = %C", ch);
//%C打印unichar字符 %c打印ASCII字符
//字符串提取
//从传入下标位置提取子串到字符串结束
NSString *subStr1 = [str1 substringFromIndex:
4];
NSLog(@"subStr1 = %@", subStr1);
//提取子串到指定位置(不包含下标位置字符)
NSString *subStr2 = [str1 substringToIndex:
7];
NSLog(@"subStr2 = %@",subStr2);
//提取指定范围内的字符串
NSRange range = {
6,
5};
NSString *subStr3 =
[str1 substringWithRange:range];
NSLog(@"subStr3 = %@", subStr3);
//NSMakeRange();//构建NSRange变量
NSString *subStr4 = [str1 substringWithRange:NSMakeRange(
2,
6)];
NSLog(@"subStr4 = %@", subStr4);
//字符串比较
NSString *str2 = [NSString stringWithCString:
"hallo world中国" encoding:NSUTF8StringEncoding];
NSString *str3 = [NSString stringWithUTF8String:
"hello world中国"];
NSComparisonResult result =
[str2 compare:str3];
if (result == NSOrderedAscending) {
//递增
NSLog(
@"str2 < str3");
}
else if(result == NSOrderedDescending)
//递减
{
NSLog(@"str2 > str3");
}
else
{
NSLog(@"str2 == str3");
}
//以大小写不敏感方式比较字符串
//[str2 caseInsensitiveCompare:str3];
//判断两个字符串是否相等
//- (BOOL)isEqualToString:(NSString *)aString;
BOOL ret =
[str2 isEqualTo:str3];
if (ret==
YES) {
NSLog(@"str2 == str3");
}
else
{
NSLog(@"str2 != str3");
}
//判断前缀子串
//- (BOOL)hasPrefix:(NSString *)aString;
BOOL ret1 = [
@"www.baidu.com" hasPrefix:
@"www."];
NSLog(@"ret1 = %d", ret1);
//判断后缀子串
//- (BOOL)hasSuffix:(NSString *)aString;
BOOL ret2 = [
@"www.hao123.com" hasSuffix:
@"com"];
NSLog(@"ret2 = %d", ret2);
//判断是否包含子串(10.10macos)
BOOL ret3 = [
@"hao123" containsString:
@"hao"];
NSLog(@"ret3 = %d", ret3);
//查找子串
NSString *str4 = [[NSString alloc] initWithFormat:
@"%s",
"hello world qianworldfeng"];
NSRange range1 =[str4 rangeOfString:
@"world"];
if (range1.location == NSNotFound) {
//不能查找对应的子串, 返回long类型最大值
NSLog(
@"没有查找到字串 notfound = %lu", NSNotFound);
}
else
{
NSLog(@"location = %lu length = %lu", range1.location, range1.length);
}
//倒序查找子串
NSRange range2 = [str4 rangeOfString:
@"world" options:NSBackwardsSearch];
NSLog(@"location = %li length = %li", range2.location, range2.length);
//字符串追加
//并不是直接在原字符串的末尾追加字符串, 而是利用传入的字符串及原字符串创建一个新的字符串
NSString *str5 =
@"hello";
NSLog(@"%p", str5);
str5 = [str5 stringByAppendingString:
@"world"];
NSLog(@"str5 = %@", str5);
NSLog(@"%p", str5);
//格式化追加字符串
NSString *str6 =
@"qianfeng";
str6 = [str6 stringByAppendingFormat:
@"%d%s",
123,
"helloworld"];
NSLog(@"str6 = %@", str6);
//把字符换串对象转换成整型 浮点型
int a = [
@"12345" intValue];
float f = [
@"3.14" floatValue];
NSLog(@"a = %d f = %.2f", a, f);
//返回公共前缀子串
NSString *str7 = [
@"www.baidu.com" commonPrefixWithString:
@"www.hao123.com" options:NSLiteralSearch];
NSLog(@"str7 = %@", str7);
//大小写转换
//把小写字母转换成大写字母
NSString *str8 = [
@"baidu中国" uppercaseString];
NSLog(@"str8 = %@", str8);
//把大写字母转换成小写字母
NSString *str9 = [
@"BaiDU" lowercaseString];
NSLog(@"str9 = %@", str9);
//把每个单词的首字母大写
NSString *str10= [
@"bai du qian feng" capitalizedString];
NSLog(@"str10 = %@", str10);
//字符串替换
//- (NSString *)stringByReplacingOccurrencesOfString:(NSString *)target withString:(NSString *)replacement
NSString *str11=
@"hello world qianfeng hello world hello hell qianfeng";
str11 = [str11 stringByReplacingOccurrencesOfString:
@"hello" withString:
@"welcome"];
NSLog(@"str11 = %@", str11);
//替换指定范围内的字符
//- (NSString *)stringByReplacingCharactersInRange:(NSRange)range withString:(NSString *)replacement
NSString *str12 =
@"hello world qianfeng";
str12 = [str12 stringByReplacingCharactersInRange:NSMakeRange(
12,
8) withString:
@"welcome"];
NSLog(@"str12 = %@", str12);
//把OC的字符串对象转换成C字符串
NSLog(
@"%s", [
@"hello world" UTF8String]);
//用网址的内容生成OC字符串对像
//- (instancetype)initWithContentsOfURL:(NSURL *)url encoding:(NSStringEncoding)enc error:(NSError **)error;
//+ (instancetype)stringWithContentsOfURL:(NSURL *)url encoding:(NSStringEncoding)enc error:(NSError **)error;
NSURL *url= [[NSURL alloc] initWithString:
@"http://www.baidu.com"];
NSString *urlContent = [[NSString alloc] initWithContentsOfURL:url encoding:NSUTF8StringEncoding error:nil];
//nil 空指针
NSLog(
@"urlContent = %@", urlContent);
//用文件的内容生成字符串
//- (instancetype)initWithContentsOfFile:(NSString *)path encoding:(NSStringEncoding)enc error:(NSError **)error;
//+ (instancetype)stringWithContentsOfFile:(NSString *)path encoding:(NSStringEncoding)enc error:(NSError **)error;
NSString *fileContent = [NSString stringWithContentsOfFile:
@"/Users/zhangxueming/Desktop/json.txt" encoding:NSUTF8StringEncoding error:nil];
NSLog(@"fileContent = %@", fileContent);
}
return 0;
}
转载于:https://www.cnblogs.com/0515offer/p/4566850.html
