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  • 【iOS】去除字符串首尾空格或某字符

    在iOS的实际开发中,常会出现需要去除空格的情况,总结有三种情况:

    • 去除字符串首尾连续字符(如空格);
    • 去除字符串首部连续字符(如空格);
    • 去除字符串尾部连续字符(如空格);

    去除字符串首尾连续字符(如空格)

     NSString *a = @" a  sdf  ";
     [a stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    

    去除字符串首部连续字符(如空格);

     NSString *a = @" a  sdf  ";  
     NSString *leftResult = [a stringByTrimmingLeftCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    
    #import "NSString+util.h"
    
    @implementation NSString (util)
    
    - (NSString *)stringByTrimmingLeftCharactersInSet:(NSCharacterSet *)characterSet {
        NSUInteger location = 0;
        NSUInteger length = [self length];
        unichar charBuffer[length];
        [self getCharacters:charBuffer range:NSMakeRange(0, length)];
        
        for (NSInteger i = 0; i < length; i++) {
            if (![characterSet characterIsMember:charBuffer[i]]) {
                location = i;
                break;
            }
        }
        
        return [self substringWithRange:NSMakeRange(location, length - location)];
    }
    

    去除字符串尾部连续字符(如空格);

    NSString *a = @" a  sdf  "; 
    NSString *rightResult = [a stringByTrimmingRightCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]; 
    
    - (NSString *)stringByTrimmingRightCharactersInSet:(NSCharacterSet *)characterSet {
        NSUInteger length = [self length];
        unichar charBuffer[length];
        [self getCharacters:charBuffer range:NSMakeRange(0, length)];
        
        NSUInteger subLength = 0;
        for (NSInteger i = length; i > 0; i--) {
            if (![characterSet characterIsMember:charBuffer[i - 1]]) {
                subLength = i;
                break;
            }
        }
        
        return [self substringWithRange:NSMakeRange(0, subLength)];
    }
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  • 原文地址:https://www.cnblogs.com/Free-Thinker/p/11429709.html
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