xcode 目标 C：检查字符串的开头
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OBjective C: check the beginning of a string
提问by cyclingIsBetter
I must verify the beginning of a string: my example string is
我必须验证字符串的开头：我的示例字符串是
NSString *string1 = @"Hello World";
then I must do an if, example:
那么我必须做一个 if，例如：
if (string1 startwith "Hello")
How can I do this in objective c?
我怎样才能在目标 c 中做到这一点？
回答by Jim Blackler
if ([string1 hasPrefix:@"Hello"])
回答by NSResponder
Read the documentation for the NSString class. You'll find all kinds of surprises.
阅读 NSString 类的文档。你会发现各种各样的惊喜。
回答by Mick Walker
How about doing it this way:
这样做怎么样：
NSRange aRange = [myString rangeOfString:@"Hello"];
if (aRange.location ==NSNotFound) {
NSLog(@"string not found");
} else {
NSLog(@"string was at index %d ",aRange.location);
}
Based on the range, you can determine where in the string the item occurs
根据范围，您可以确定项目出现在字符串中的哪个位置
