反向NSString文本 [英] Reverse NSString text

问题描述

我一直在googling这么多，如何做到这一点，但如何颠倒NSString？例如：hi会变成：ih

I have been googling so much on how to do this, but how would I reverse a NSString? Ex:hi would become: ih

我正在寻找最简单的方法。

I am looking for the easiest way to do this.

@我做了这个方法：

- (IBAction)doneKeyboard {

// first retrieve the text of textField1
NSString *myString = field1.text;
NSMutableString *reversedString = [NSMutableString string];
NSUInteger charIndex = 0;
while(myString && charIndex < [myString length]) {
    NSRange subStrRange = NSMakeRange(charIndex, 1);
    [reversedString appendString:[myString substringWithRange:subStrRange]];
    charIndex++;
}
// reversedString is reversed, or empty if myString was nil
field2.text = reversedString;
}

我将该方法连接到textfield1的didendonexit。当我单击完成按钮，它不会反转文本，UILabel只显示我输入的UITextField的文本。错误？

I hooked up that method to textfield1's didendonexit. When I click the done button, it doesn't reverse the text, the UILabel just shows the UITextField's text that I entered. What is wrong?

推荐答案

编写一个简单的循环：

// myString is "hi"
NSMutableString *reversedString = [NSMutableString string];
NSInteger charIndex = [myString length];
while (charIndex > 0) {
    charIndex--;
    NSRange subStrRange = NSMakeRange(charIndex, 1);
    [reversedString appendString:[myString substringWithRange:subStrRange]];
}
NSLog(@"%@", reversedString); // outputs "ih"

在您的情况下：

In your case:

// first retrieve the text of textField1
NSString *myString = textField1.text;
NSMutableString *reversedString = [NSMutableString string];
NSInteger charIndex = [myString length];
while (myString && charIndex > 0) {
    charIndex--;
    NSRange subStrRange = NSMakeRange(charIndex, 1);
    [reversedString appendString:[myString substringWithRange:subStrRange]];
}
// reversedString is reversed, or empty if myString was nil
textField2.text = reversedString;

这篇关于反向NSString文本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！