有沒有辦法計算NSString的行數？

Question

可能重複：
How to count the number of lines in an Objective-C string (NSString)?

有沒有一種方法來計算一個的NSString的行數？

NSString * myString = @"line 1 \n line 2 \n"; 

lines = 3;

謝謝

Answer 1

請嘗試下面的代碼。

NSString * myString = @"line 1 \n line 2 \n"; 
NSArray *list = [myString componentsSeparatedByString:@"\n"]; 
NSLog(@"No of lines : %d",[list count]); 

Answer 2

試試這個

NSString * myString = @"line 1 \n line 2 \n"; 
int count = [[myString componentsSeparatedByString:@"\n"] count]; 
NSLog(@"%d", count); 

Answer 3

謹防componentsSeparatedByString是不不夠聰明MAC /窗/ Unix行結尾之間檢測。分離\n將適用於windows/unix行結尾，但不適用於傳統的mac文件（並且有一些流行的mac編輯器仍默認使用這些文件）。你真的應該檢查\r\n和\r。

此外，componentsSeparatedByString:是緩慢和內存飢餓。如果你關心性能，你應該反覆搜索新行和計算結果的數量：

NSString * myString = @"line 1 \n line 2 \n"; 

int lineCount = 1; 
NSUInteger characterLocation = 0; 
NSCharacterSet *newlineCharacterSet = [NSCharacterSet newlineCharacterSet]; 
while (characterLocation < myString.length) { 
    characterLocation = [myString rangeOfCharacterFromSet:newlineCharacterSet options:NSLiteralSearch range:NSMakeRange(characterLocation, (myString.length - characterLocation))].location; 

    if (characterLocation == NSNotFound) { 
    break; 
    } 

    // if we are at a \r character and the next character is a \n, skip the next character 
    if (myString.length >= characterLocation && 
     [myString characterAtIndex:characterLocation] == '\r' && 
     [myString characterAtIndex:characterLocation + 1] == '\n') { 
    characterLocation++; 
    } 

    lineCount++; 
    characterLocation++; 
} 

NSLog(@"%i", lineCount);