Auto Layout Programmatically

gistfile1.m

UITextField *textField1 = [UITextField new];
    textField1.placeholder = @"UITextField 1";
    textField1.borderStyle = UITextBorderStyleRoundedRect;
    textField1.backgroundColor = [UIColor redColor];
    [textField1 setTranslatesAutoresizingMaskIntoConstraints:NO];
    [self.view addSubview:textField1];
    
    UITextField *textField2 = [UITextField new];
    textField2.placeholder = @"UITextField 2";
    textField2.borderStyle = UITextBorderStyleRoundedRect;
    textField2.backgroundColor = [UIColor blueColor];
    [textField2 setTranslatesAutoresizingMaskIntoConstraints:NO];
    [self.view addSubview:textField2];
    
    NSLayoutConstraint *leadingConstraint =
    [NSLayoutConstraint constraintWithItem:textField1
                                 attribute:NSLayoutAttributeLeading
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:self.view
                                 attribute:NSLayoutAttributeLeading
                                multiplier:1.0
                                  constant:10];
    [self.view addConstraint:leadingConstraint];
    
    NSLayoutConstraint *trailingConstraint =
    [NSLayoutConstraint constraintWithItem:textField2
                                 attribute:NSLayoutAttributeTrailing
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:self.view
                                 attribute:NSLayoutAttributeTrailing
                                multiplier:1.0
                                  constant:-10];
    [self.view addConstraint:trailingConstraint];
    
    NSLayoutConstraint *top1Constraint =
    [NSLayoutConstraint constraintWithItem:textField1
                                 attribute:NSLayoutAttributeTop
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:self.view
                                 attribute:NSLayoutAttributeTop
                                multiplier:1.0
                                  constant:35];
    [self.view addConstraint:top1Constraint];
    
    NSLayoutConstraint *top2Constraint =
    [NSLayoutConstraint constraintWithItem:textField2
                                 attribute:NSLayoutAttributeTop
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:self.view
                                 attribute:NSLayoutAttributeTop
                                multiplier:1.0
                                  constant:35];
    [self.view addConstraint:top2Constraint];
    
    NSLayoutConstraint *equalWidthConstraint =
    [NSLayoutConstraint constraintWithItem:textField1
                                 attribute:NSLayoutAttributeWidth
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:textField2
                                 attribute:NSLayoutAttributeWidth
                                multiplier:1.0
                                  constant:0];
    [self.view addConstraint:equalWidthConstraint];
    
    NSLayoutConstraint *spacingConstraint =
    [NSLayoutConstraint constraintWithItem:textField2
                                 attribute:NSLayoutAttributeLeading
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:textField1
                                 attribute:NSLayoutAttributeTrailing
                                multiplier:1.0
                                  constant:-10];
    [self.view addConstraint:spacingConstraint];