如何检查字符串是否包含Objective-C中的另一个字符串?

时间:2010-05-02 15:34:54

标签: ios objective-c string substring

如何检查字符串(NSString)是否包含另一个较小的字符串?

我希望有类似的东西:

NSString *string = @"hello bla bla";
NSLog(@"%d",[string containsSubstring:@"hello"]);

但我能找到的最接近的是:

if ([string rangeOfString:@"hello"] == 0) {
    NSLog(@"sub string doesnt exist");
} 
else {
    NSLog(@"exists");
}

无论如何,这是查找字符串是否包含另一个字符串的最佳方法吗?

23 个答案:

答案 0 :(得分:2411)

NSString *string = @"hello bla bla";
if ([string rangeOfString:@"bla"].location == NSNotFound) {
  NSLog(@"string does not contain bla");
} else {
  NSLog(@"string contains bla!");
}

如果“haystack”不包含“needle”,则注意rangeOfString:返回NSRange结构,而the documentation says返回结构{NSNotFound, 0}


如果您使用的是iOS 8或OS X Yosemite,您现在可以:(*注意:如果在iOS7设备上调用此代码,这将使您的应用程序崩溃)。

NSString *string = @"hello bla blah";
if ([string containsString:@"bla"]) {
  NSLog(@"string contains bla!");
} else {
  NSLog(@"string does not contain bla");
}

(这也是它在Swift中的工作方式)

答案 1 :(得分:158)

注意:此答案现已过时

为NSString创建一个类别:

@interface NSString ( SubstringSearch )
    - (BOOL)containsString:(NSString *)substring;
@end

// - - - - 

@implementation NSString ( SubstringSearch )

- (BOOL)containsString:(NSString *)substring
{    
    NSRange range = [self rangeOfString : substring];
    BOOL found = ( range.location != NSNotFound );
    return found;
}

@end

编辑:观察Daniel Galasko关于命名的以下评论

答案 2 :(得分:51)

由于这似乎是Google的高排名结果,我想补充一下:

iOS 8和OS X 10.10将containsString:方法添加到NSString。这些系统的Dave DeLong示例的更新版本:

NSString *string = @"hello bla bla";
if ([string containsString:@"bla"]) {
    NSLog(@"string contains bla!");
} else {
    NSLog(@"string does not contain bla");
}

答案 3 :(得分:39)

NSString *myString = @"hello bla bla";
NSRange rangeValue = [myString rangeOfString:@"hello" options:NSCaseInsensitiveSearch];

if (rangeValue.length > 0)
{
    NSLog(@"string contains hello");
} 
else 
{
    NSLog(@"string does not contain hello!");
}

//您也可以使用以下内容:

if (rangeValue.location == NSNotFound) 
{
    NSLog(@"string does not contain hello");
} 
else 
{
    NSLog(@"string contains hello!");
}

答案 4 :(得分:22)

使用 iOS 8 Swift ,我们可以使用localizedCaseInsensitiveContainsString方法

 let string: NSString = "Café"
 let substring: NSString = "É"

 string.localizedCaseInsensitiveContainsString(substring) // true

答案 5 :(得分:13)

所以我个人非常讨厌NSNotFound,但要明白其必要性。

但有些人可能不理解与NSNotFound比较的复杂性

例如,此代码:

- (BOOL)doesString:(NSString*)string containString:(NSString*)otherString {
    if([string rangeOfString:otherString].location != NSNotFound)
        return YES;
    else
        return NO;
}

有问题:

1)显然,otherString = nil此代码会崩溃。一个简单的测试是:

NSLog(@"does string contain string - %@", [self doesString:@"hey" containString:nil] ? @"YES": @"NO");

结果!!撞死!!

2)对于Objective-c的新手来说,不那么明显的是string = nil时相同的代码不会崩溃。 例如,此代码:

NSLog(@"does string contain string - %@", [self doesString:nil containString:@"hey"] ? @"YES": @"NO");

和这段代码:

NSLog(@"does string contain string - %@", [self doesString:nil containString:nil] ? @"YES": @"NO");

将导致

does string contains string - YES

这显然不是你想要的。

所以我认为更好的解决方案是使用rangeOfString返回长度为0的事实,这样一个更可靠的代码是这样的:

- (BOOL)doesString:(NSString*)string containString:(NSString*)otherString {
    if(otherString && [string rangeOfString:otherString].length)
        return YES;
    else
        return NO;
}

或简单:

- (BOOL)doesString:(NSString*)string containString:(NSString*)otherString {
    return (otherString && [string rangeOfString:otherString].length);
}

将针对案例1和2返回

does string contains string - NO

那是我的2美分; - )

请查看我的Gist以获取更多有用的代码。

答案 6 :(得分:12)

NSString上的一个类别P i's solution的改进版本,它不仅可以告诉我,如果在另一个字符串中找到一个字符串,又通过引用获取范围,那么:

@interface NSString (Contains)
-(BOOL)containsString: (NSString*)substring
              atRange:(NSRange*)range;

-(BOOL)containsString:(NSString *)substring;
@end

@implementation NSString (Contains)

-(BOOL)containsString:(NSString *)substring
              atRange:(NSRange *)range{

    NSRange r = [self rangeOfString : substring];
    BOOL found = ( r.location != NSNotFound );
    if (range != NULL) *range = r;
    return found;
}

-(BOOL)containsString:(NSString *)substring
{
    return [self containsString:substring
                        atRange:NULL];
}

@end

使用它像:

NSString *string = @"Hello, World!";

//If you only want to ensure a string contains a certain substring
if ([string containsString:@"ello" atRange:NULL]) {
    NSLog(@"YES");
}

// Or simply
if ([string containsString:@"ello"]) {
    NSLog(@"YES");
}

//If you also want to know substring's range
NSRange range;
if ([string containsString:@"ello" atRange:&range]) {
    NSLog(@"%@", NSStringFromRange(range));
}

答案 7 :(得分:8)

以下是复制粘贴功能代码段:

-(BOOL)Contains:(NSString *)StrSearchTerm on:(NSString *)StrText
{
    return [StrText rangeOfString:StrSearchTerm 
        options:NSCaseInsensitiveSearch].location != NSNotFound;
}

答案 8 :(得分:6)

Oneliner(代码量较少。干,因为你只有一个NSLog):

NSString *string = @"hello bla bla";
NSLog(@"String %@", ([string rangeOfString:@"bla"].location == NSNotFound) ? @"not found" : @"cotains bla"); 

答案 9 :(得分:6)

NSString *categoryString = @"Holiday Event";
if([categoryString rangeOfString:@"Holiday"].location == NSNotFound)
{
    //categoryString does not contains Holiday
}
else
{
    //categoryString contains Holiday
}

答案 10 :(得分:5)

最佳解决方案。就这么简单!如果你想找一个单词或 字符串的一部分。您可以使用此代码。在这个例子中,我们将检查word的值是否包含" acter"。

NSString *word =@"find a word or character here";
if ([word containsString:@"acter"]){
    NSLog(@"It contains acter");
} else {
     NSLog (@"It does not contain acter");
}

答案 11 :(得分:5)

试试这个,

NSString *string = @"test Data";
if ([[string lowercaseString] rangeOfString:@"data"].location == NSNotFound) 
{
    NSLog(@"string does not contain Data");
}   
else 
{
    NSLog(@"string contains data!");
}

答案 12 :(得分:4)

在Swift 4中:

let a = "Hello, how are you?"
a.contains("Hello")   //will return true

答案 13 :(得分:4)

如果是swift,可以使用

let string = "Package #23"
if string.containsString("Package #") {
    //String contains substring
}
else {
    //String does not contain substring
}

答案 14 :(得分:4)

如果你需要这一次写:

NSString *stringToSearchThrough = @"-rangeOfString method finds and returns the range of the first occurrence of a given string within the receiver.";
BOOL contains = [stringToSearchThrough rangeOfString:@"occurence of a given string"].location != NSNotFound;

答案 15 :(得分:2)

如果不打扰区分大小写的字符串。  试一试。

NSString *string  = @"Hello World!";

if([string rangeOfString:@"hello" options:NSCaseInsensitiveSearch].location !=NSNotFound)
{
    NSLog(@"found");
}
else
{
    NSLog(@"not found");
}

答案 16 :(得分:1)

使用选项NSCaseInsensitiveSearch和rangeOfString:options:

NSString *me = @"toBe" ;
NSString *target = @"abcdetobe" ;
NSRange range = [target  rangeOfString: me options: NSCaseInsensitiveSearch];
NSLog(@"found: %@", (range.location != NSNotFound) ? @"Yes" : @"No");
if (range.location != NSNotFound) {
// your code
}

找到输出结果:是

选项可以是"或'"一起并包括:

NSCaseInsensitiveSearch NSLiteralSearch NSBackwardsSearch等等

答案 17 :(得分:1)

请使用此代码

NSString *string = @"hello bla bla";
if ([string rangeOfString:@"bla"].location == NSNotFound) 
{
    NSLog(@"string does not contain bla");
} 
else 
{  
    NSLog(@"string contains bla!");
}

答案 18 :(得分:0)

第一个字符串包含或不包含第二个字符串

NSString *first = @"Banana";
NSString *second = @"BananaMilk";
NSRange range = [first rangeOfString:second options:NSCaseInsensitiveSearch];

if (range.length > 0) {
    NSLog(@"Detected");
}
else {
    NSLog(@"Not detected");
}

答案 19 :(得分:0)

SWift 4及以上

 let str = "Hello iam midhun"

   if str.contains("iam") {
     //contain substring
   }
   else {
     //doesn't contain substring
   }

答案 20 :(得分:0)

尝试一下:

Swift 4.1、4.2:

let stringData = "Black board"

//swift quick way and case sensitive
if stringData.contains("bla") {
    print("data contains string");
}

//case sensitive
if stringData.range(of: "bla",options: .caseInsensitive) != nil {
    print("data contains string");
}else {
    print("data does not contains string");
}

对于Objective-C:

NSString *stringData = @"Black board";

//Quick way and case sensitive
if ([stringData containsString:@"bla"]) {
    NSLog(@"data contains string");
}

//Case Insensitive
if ([stringData rangeOfString:@"bla" options:NSCaseInsensitiveSearch].location != NSNotFound) {
   NSLog(@"data contains string");
}else {
   NSLog(@"data does not contain string");
}

答案 21 :(得分:-1)

hoverable

答案 22 :(得分:-2)

如果需要字符串的某个位置,此代码将放在 Swift 3.0 中:

input