我如何检查一个字符串(NSString)包含另一个较小的字符串?
我希望是这样的:
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");
}
不管怎样，这是找出字符串是否包含另一个字符串的最好方法吗?
当前回答
i的解决方案的一个改进版本，NSString上的一个类别，它不仅会告诉，如果一个字符串在另一个字符串中被找到，而且还需要一个引用范围，是:
@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));
}
其他回答
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
如果你需要这样做，可以这样写:
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;
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!");
}
//你也可以使用下面的语句:
if (rangeValue.location == NSNotFound)
{
NSLog(@"string does not contain hello");
}
else
{
NSLog(@"string contains hello!");
}
NSString *string = @"hello bla bla";
if ([string rangeOfString:@"bla"].location == NSNotFound) {
NSLog(@"string does not contain bla");
} else {
NSLog(@"string contains bla!");
}
关键是注意到rangeOfString:返回一个NSRange结构体，并且文档说如果“haystack”不包含“needle”，它返回结构体{NSNotFound, 0}。
如果你在iOS 8或OS X Yosemite上，你现在可以这样做:*(注意:如果在iOS7设备上调用此代码，这将使你的应用程序崩溃)。
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)
Swift 4及以上
let str = "Hello iam midhun"
if str.contains("iam") {
//contains substring
}
else {
//doesn't contain substring
}
objective - c
NSString *stringData = @"Hello iam midhun";
if ([stringData containsString:@"iam"]) {
//contains substring
}
else {
//doesn't contain substring
}
