NSString
1.赋值
NSString *s1 = @“123”;
2.初始化方法
NSString *s2 = [[NSString alloc]init];
3. 便利构造器
NSString *s3 = [NSString string];
4.格式化初始化字符串
NSString *s4 = [[NSString alloc]initWithFormat:@“boomshakalaka”];
NSString *s5 = [NSString stringWithFormat:@“lalalala”];
NSString *s6 = [NSString stringWithFormat:@“%@shakalaka”,@“boom”];
NSString *ss = [NSString stringWithFormat:@“%dlalala”,8];
5.通过路径获取字符串
NSString * s7 = [NSString stringWithContentsOfFile:@“路径”encoding:NSUTF8StringEncoding error:nil];
6.字符串长度g
NSlog(@“%lu“,[s6 length];
7.判断是否有前后缀
NSString *s8 = @“abc123”;
BOOL b1 = [s8 hasPrefix:@“abc”];
BOOL b2 = [s8 hasSuffix:@“3”];
NSLog(@“%d”,b1);
NSLog(@“%d”,b2);
8.大小写转换
小->大
NSString * s9 = [s8 uppercaseString];
NSLog(@“%@“,s9);
大->小
NSString * s10 = [s9 lowercaseString];
NSLog(@“%@“,s10);
9.比较两个字符串大小
NSComparisonResult r1 = [s8 compare:@“b”];
NSLog(@“%ld”,r1);
10.比较字符串是否相等
BOOL b3 = [s8 isEqualToString:s9];
NSLog(@“%d”,b3);
11.获取某个位置的字符
NSLog(@“%c”,[s8 characterAtIndex:1]);
NSString * s11 = [s8 substringFromIndex:1];
NSLog(@“%@“,s11);
NSString * s12 = [s8 substringToIndex:1];
NSLog(@“%@“,s12);
NSString * s13 = [s8 substringWithRange:NSMakRange(3,3)];
NSLog(@“%@“,s13);
NSMutableString
1.赋值
NSMutableString *ms1 = [NSMutableString stringWithFormat:@“456”];
NSLog(@“%@“,ms1);
2.改值或设置值
[ms1 setString:@“789”];
NSLog(@“%@“,ms1);
3.拼接
[ms1 appendString:@“123”];
NSLog(@“%@“,ms1);
[ms1 appendFormat:@“123%d”,5];
NSLog(@“%@“,ms1);
4.替换
[ms1 replaceCharatersInRange:NSMakeRange(3,3) withString:@“456”];
NSLog(@“%@“,ms1);
5.删除
[ms1 deleteCharatersInRange:NSMakeRange(9,1)];
NSLog(@“%@“,ms1);
6.插入
[ms1 insertString:@“0” atIndex:0];
NSLog(@“%@“,ms1);
7.首字母大写
NSMutableString *aa = [NSMutableString stringWithFormat:@"i love you"];
NSString *ss = [aa capitalizedString];
NSLog(@"%@",ss);
NSArray
1.初始化方法
NSArray *arr1 = [[NSArray alloc]initWithObjects:@“1”,@“2”,@“3”,nil];
NSLog(@“%@”,arr1);
2.便利构造器
NSArray *arr2 = [NSArray arrayWithObjects:@“4”,@“5”,@“6”,nil];
NSLog(@“%@“,arr2);
3.利用数组初始化数组
NSArray *arr3 = [NSArray arrayWithArray:arr2 ];
NSLog(@“%@”,arr3);
4. 字面量初始化数组
NSArray *arr4 = @[@“7”,@“8”,@“9”];
NSLog(@“%@”,arr4);
5.计算数组元素个数
NSInteger ui1 = [arr4 count];
NSLog(@“%lu”,ui1);
6.取出数组元素下标
NSINteger ui2 = [arr4 indexOfObject:@“9”];
NSLog(@“%lu”,ui2);
7.取出下标对应的元素
NSLog(@“%@“,[arr4 objectAtIndex:1]);
NSMutableArray
1.初始化数组
NSMutableArray *mArr1 = [NSMutableArray arrayWithObjects:@"1",@"2",@"3", nil];
2.添加
[mArr1 addObject:@"4"];
[mArr1 addObject:@"5"];
NSLog(@"%@",mArr1);
3.删除
[mArr1 removeLastObject];-[mArr1 removeAllObjects];//删除全部
NSLog(@"%@",mArr1);
[mArr1 removeObject:@"4"];
NSLog(@"%@",mArr1);
4.删除下标所在元素
[mArr1 removeObjectAtIndex:0];
NSLog(@"%@",mArr1);
5. 插入
[mArr1 insertObject:@"1"atIndex:0];
NSLog(@"%@",mArr1);
6.替换
[mArr1 replaceObjectAtIndex:0withObject:@"3"];
[mArr1 replaceObjectAtIndex:1 withObject:@"3"];
NSLog(@"%@",mArr1);
NSNumber
1.将基本数据类型转换成对象类型
int i = 1;
long l = 20000;
NSNumber *number1 = [[NSNumber alloc]initWithInt:i];
2.NSNumber 类型也可以转化成int类型
int a1 = [number1 intValue];
NSLog(@"%d",a1);
NSNumber *number2 = [[NSNumber alloc]initWithLong:l];
NSLog(@"%@",number1);
NSLog(@"%@",number2);
NSString *string = @"123";
3.将字符串转化成 整型
int a2 = [string intValue];
NSLog(@"%d",a2);
4.将NSNumber转化成 字符串
[number2 stringValue];
NSLog(@"%@",number2);