ios 如何将字符串附加到 NSMutableString
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How to append a string to NSMutableString
提问by murze
i'm an absolute newbie with objective-c
我是 Objective-c 的绝对新手
with this code
用这个代码
NSMutableString *teststring;
[teststring appendString:@"hey"];
NSLog(teststring);
nothing gets displayed in the console.
控制台中没有显示任何内容。
Surely i'm doing something wrong here... :-)
当然我在这里做错了什么...... :-)
回答by Apurv
You need to create the string first.
您需要先创建字符串。
NSMutableString *teststring = [[NSMutableString alloc]init];
[teststring appendString:@"hey"];
NSLog(teststring);
Now, it will print.
现在，它将打印。
回答by Shmidt
Change first line to
将第一行更改为
NSMutableString *teststring = [NSMutableString string];
回答by PengOne
This line
这条线
NSMutableString *teststring;
simply establishes a pointer, but does not create anything. Instead, you need to create a new instance of NSMutableString, for example:
只是建立一个指针，但不创建任何东西。相反，您需要创建 的新实例NSMutableString，例如：
NSMutableString *teststring = [[NSMutableString alloc] init];
[teststring appendString:@"hey"];
NSLog("%@", teststring);
回答by Sly
Sample:
样本：
NSMutableString *buffer = [[NSMutableString alloc] init]; // retain count = 1. Because of the "alloc", you have to call a release later
[buffer appendString:@"abc"];
NSLog(@"1 : %@", buffer);
[buffer appendString:@"def"];
NSLog(@"2 : %@", buffer);
[buffer release]; // retain count = 0 => delete object from memory
回答by Movses Karapetyan
NSMutableString *tag = [NSMutableString stringWithString: @"hello <td> this is inside td </td> 000999 <><> ..<. ><> 00000 <td>uuuuu</td> vvvvv <td> this is also inside td </td>"];
NSRange open = [tag rangeOfString:@"<"];
while(open.location != NSNotFound)
{
NSRange close = [tag rangeOfString:@">"];
NSRange string = NSMakeRange(open.location, close.location-open.location+1);
[tag replaceCharactersInRange:string withString:@""];
open = [tag rangeOfString:@"<"];
NSLog(@"%@",tag);
}
