如何检查一个字符串在Objective-C中是否包含另一个字符串？

如何检查字符串（NSString）是否包含另一个较小的字符串？

我希望有这样的东西：

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

但是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，这是查找一个字符串是否包含另一个字符串的最佳方法吗？

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

关键是要注意rangeOfString:返回一个NSRange结构，并且文档说{NSNotFound, 0}如果“干草堆”中不包含“ needle” ，它将返回该结构。

而且，如果您使用的是iOS 8或OS X Yosemite，则可以执行以下操作：（*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）

👍

对于iOS 8.0+和macOS 10.10+，您可以使用NSString的native containsString:。

对于旧版本的iOS和macOS，您可以为NSString创建自己的（过时）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

注意：请注意以下有关命名的Daniel Galasko的评论

由于这似乎是Google的高排名结果，因此我想添加以下内容：

iOS 8和OS X 10.10将containsString:方法添加到中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");
}

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!");
}

//您也可以使用以下方法：

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

在iOS 8和Swift中，我们可以使用localizedCaseInsensitiveContainsString 方法

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

 string.localizedCaseInsensitiveContainsString(substring) // true

所以我个人非常讨厌 NSNotFound但了解其必要性。

但是有些人可能不了解与NSNotFound进行比较的复杂性

例如，此代码：

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

有它的问题：

1）显然，如果otherString = nil此代码将崩溃。一个简单的测试将是：

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

结果是 ！！崩溃！

2）对于Objective-c新手来说，不太明显的是，当时，相同的代码不会崩溃string = nil。例如，此代码：

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

和此代码：

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

都会导致

does string contains string - YES

显然这不是您想要的。

因此，我认为更好的解决方案是使用rangeOfString返回长度为0的事实，因此这样的代码更可靠：

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

或简单地：

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

对于情况1和2将返回

does string contains string - NO

那是我的2美分;-)

请查看我的Gist以获得更多有用的代码。

P i解决方案的改进版本（NSString上的一个类别）不仅可以告诉您是否在另一个字符串中找到了一个字符串，而且还可以引用一个范围：

@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

像这样使用它：

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));
}

这是一个复制粘贴功能代码段：

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

Oneliner（少量的代码。DRY，因为您只有一个NSLog）：

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

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

尝试这个，

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

最佳解决方案。就这么简单！如果要查找单词或字符串的一部分。您可以使用此代码。在此示例中，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");
}

在Swift 4中：

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

如果需要一次，请写：

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;

万一迅速，可以使用

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

如果不关心区分大小写的字符串。尝试一次。

NSString *string  = @"Hello World!";

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

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!");
}

将选项NSCaseInsensitiveSearch与rangeOfString：options一起使用：

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

这些选项可以一起“或”，包括：

NSCaseInsensitiveSearch NSLiteralSearch NSBackwardsSearch等

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");
}

尝试这个：

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");
}

斯威夫特4及以上

let str = "Hello iam midhun"

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

目标C

NSString *stringData = @"Hello iam midhun";

if ([stringData containsString:@"iam"]) {
    //contains substring
}
else {
    //doesn't contain substring
}

-(Bool)checkIf:(String)parentString containsSubstring:(String)checkString {
    NSRange textRange =[parentString rangeOfString:checkString];
    return textRange.location != NSNotFound // returns true if parent string contains substring else returns false
  }

如果需要字符串的特定位置，则此代码将放置在Swift 3.0中：

let string = "This is my string"
let substring = "my"

let position = string.range(of: substring)?.lowerBound