在Objective-C中有没有(stringByAppendingString:)字符串连接的快捷方式，或者一般使用NSString的快捷方式?
例如，我想做:
NSString *myString = @"This";
NSString *test = [myString stringByAppendingString:@" is just a test"];
更像是:
string myString = "This";
string test = myString + " is just a test";
当前回答
我喜欢的方法是:
NSString *firstString = @"foo";
NSString *secondString = @"bar";
NSString *thirdString = @"baz";
NSString *joinedString = [@[firstString, secondString, thirdString] join];
你可以通过在NSArray中添加join方法来实现:
#import "NSArray+Join.h"
@implementation NSArray (Join)
-(NSString *)join
{
return [self componentsJoinedByString:@""];
}
@end
@[]是NSArray的简短定义，我认为这是连接字符串最快的方法。
如果你不想使用类别，直接使用componentsJoinedByString:方法:
NSString *joinedString = [@[firstString, secondString, thirdString] componentsJoinedByString:@""];
其他回答
我一直在看这篇文章，最后总是整理答案，找到一个简单的解决方案，可以根据需要处理尽可能多的变量:
[NSString stringWithFormat:@"%@/%@/%@", three, two, one];
例如:
NSString *urlForHttpGet = [NSString stringWithFormat:@"http://example.com/login/username/%@/userid/%i", userName, userId];
正在尝试在lldb窗格中执行以下操作
[NSString stringWithFormat:@"%@/%@/%@", three, two, one];
这错误。
而是使用alloc和initWithFormat方法:
[[NSString alloc] initWithFormat:@"%@/%@/%@", @"three", @"two", @"one"];
NSString *label1 = @"Process Name: ";
NSString *label2 = @"Process Id: ";
NSString *processName = [[NSProcessInfo processInfo] processName];
NSString *processID = [NSString stringWithFormat:@"%d", [[NSProcessInfo processInfo] processIdentifier]];
NSString *testConcat = [NSString stringWithFormat:@"%@ %@ %@ %@", label1, processName, label2, processID];
尝试stringWithFormat:
NSString *myString = [NSString stringWithFormat:@"%@ %@ %@ %d", "The", "Answer", "Is", 42];
当为web服务构建请求时，我发现像下面这样做非常容易，并且在Xcode中使连接可读:
NSString* postBody = {
@"<?xml version=\"1.0\" encoding=\"utf-8\"?>"
@"<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">"
@" <soap:Body>"
@" <WebServiceMethod xmlns=\"\">"
@" <parameter>test</parameter>"
@" </WebServiceMethod>"
@" </soap:Body>"
@"</soap:Envelope>"
};
