How to find string length for the multi language sentence in IOS

Question

I am developing an application that needs to restrict user from entering string text unto 200 characters.

The user is allowed to enter string value in any language.

I am able to get the string length for the english characters but not for the other languages.

Can any one help me.

Expected Result:

• 'Roger is a nice guy' -19
• 'रॉजर एक छान माणूस आहे' - 16
• '罗杰是一个好人' - 7

Answer 1

You are probably looking for extended grapheme clusters, which is a good definition of a user perceived character. Swift String's character view provides this conveniently.

Cocoa's NSString provides enumerateSubstringsInRange:options:usingBlock: which can be used to count "composed character sequences", which is similar:

@interface NSString (ComposedCharacterSequenceCount)
@property (nonatomic, readonly, getter=nr_composedCharacterSequenceCount) NSInteger composedCharacterSequenceCount;
@end

@implementation NSString (ComposedCharacterSequenceCount)
- (NSInteger)nr_composedCharacterSequenceCount
{
    __block NSInteger count = 0;
    [self enumerateSubstringsInRange:(NSRange){0, self.length}
                             options:NSStringEnumerationByComposedCharacterSequences | NSStringEnumerationSubstringNotRequired
                          usingBlock:^(NSString * _Nullable substring, NSRange substringRange, NSRange enclosingRange, BOOL * _Nonnull stop) {
                              count += 1;
                          }];
    return count;
}
@end

This snippet adds a category to NSString that lets your easily calculate the number of characters:

NSLog(@"count: %@", @(@"Roger is a nice guy".composedCharacterSequenceCount));
NSLog(@"count: %@", @(@"रॉजर एक छान माणूस आहे".composedCharacterSequenceCount));
NSLog(@"count: %@", @(@"罗杰是一个好人".composedCharacterSequenceCount));

prints:

count: 19
count: 16
count: 7