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

对于所有Objective C爱好者,在ui测试中需要这个:

-(void) clearTextField:(XCUIElement*) textField{

    NSString* currentInput = (NSString*) textField.value;
    NSMutableString* deleteString = [NSMutableString new];

    for(int i = 0; i < currentInput.length; ++i) {
        [deleteString appendString: [NSString stringWithFormat:@"%c", 8]];
    }
    [textField typeText:deleteString];
}

其他回答

一个选项:

[NSString stringWithFormat:@"%@/%@/%@", one, two, three];

另一个选择:

我猜你不满意多个追加(a+b+c+d),在这种情况下,你可以这样做:

NSLog(@"%@", [Util append:one, @" ", two, nil]); // "one two"
NSLog(@"%@", [Util append:three, @"/", two, @"/", one, nil]); // three/two/one

使用类似于

+ (NSString *) append:(id) first, ...
{
    NSString * result = @"";
    id eachArg;
    va_list alist;
    if(first)
    {
        result = [result stringByAppendingString:first];
        va_start(alist, first);
        while (eachArg = va_arg(alist, id)) 
        result = [result stringByAppendingString:eachArg];
        va_end(alist);
    }
    return result;
}

我试过这个代码。这对我很有效。

NSMutableString * myString=[[NSMutableString alloc]init];
myString=[myString stringByAppendingString:@"first value"];
myString=[myString stringByAppendingString:@"second string"];

这样使用stringByAppendingString:

NSString *string1, *string2, *result;

string1 = @"This is ";
string2 = @"my string.";

result = [result stringByAppendingString:string1];
result = [result stringByAppendingString:string2];

OR

result = [result stringByAppendingString:@"This is "];
result = [result stringByAppendingString:@"my string."];

如何缩短stringByAppendingString和使用#define:

#define and stringByAppendingString

因此你可以使用:

NSString* myString = [@"Hello " and @"world"];

问题是它只适用于两个字符串,你需要包装额外的括号更多的追加:

NSString* myString = [[@"Hello" and: @" world"] and: @" again"];

当处理字符串时,我经常发现使源文件objc++更容易,然后我可以使用问题中显示的第二个方法连接std::字符串。

std::string stdstr = [nsstr UTF8String];

//easier to read and more portable string manipulation goes here...

NSString* nsstr = [NSString stringWithUTF8String:stdstr.c_str()];