objective-c - ios ,关于方法被弃用的问题？

Question

比如，一个方法在iOS8.0 被弃用了，我们都替换成苹果建议使用的方法，那如果iOS8.0之前的版本手机，装上了这个应用。因为8.0之前没有替换后的方法，那调用到这个方法的时候，会不会出现什么问题？

例如：

Answer 1

If this method was added after ios8, then if the phone is still running on ios7, an error will occur. This is the same as android and requires manual control.

Answer 2

The deprecation is actually just no longer updated. In fact, it can still be used but there will be a warning. If you think manual control is more troublesome, you can still use this method.

Answer 3

There will be problems and even crashes.

For the case of method Deprecated, it can generally be handled like the following:

NSString *sampleString = @"abcdefg";
if ([sampleString respondsToSelector:@selector(stringByReplacingPercentEscapesUsingEncoding:)]) {
    [sampleString stringByReplacingPercentEscapesUsingEncoding:<#your-encoding-here#>];
}
else {
    <#your-else-code-here#>
}