NSMutableString *strM = [NSMutableString stringWithFormat:@"itHeiMaAndroid"];
[strM replaceOccurrencesOfString:@"Android" withString:@"iOS" options:NSLiteralSearch range:NSMakeRange(0, [strM length])];
还有就是这个方法的用法不太懂，有给讲解一下的没

NSMutableString *strM = [NSMutableString stringWithFormat:@"itHeiMaAndroid"];
[strM replaceOccurrencesOfString:@"Android" withString:@"iOS" options:NSLiteralSearch range:NSMakeRange(0, [strM length])];
还有就是这个方法的用法不太懂，有给讲解一下的没