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
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!");
}
其他回答
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!");
}
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));
}
对于iOS 8.0+和macOS 10.10+，你可以使用NSString的本地containsString:。
对于旧版本的iOS和macOS，你可以为NSString创建自己的(过时的)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:观察Daniel Galasko下面关于命名的评论
联机(更少的代码。DRY，因为你只有一个NSLog):
NSString *string = @"hello bla bla";
NSLog(@"String %@", ([string rangeOfString:@"bla"].location == NSNotFound) ? @"not found" : @"cotains bla");
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
}
