我正在阅读一个教程,并在尝试将用户添加到我的数据库时想出了这个错误语句.我正在试图弄清楚如何正确阅读这些错误陈述.例如,我看到输出显示语法错误,意外的tASSOC.期待keyword_end.所以为了在发布之前尝试解决这个问题,我在user.rb文件中注释掉了这一行(语句指向的那一行).但那没用.我还添加了一个额外的"结束",因为终端输出表示"期待keyword_end".
这是确切的终端输出:
SyntaxError: /Users/zkidd/Sites/rails_projects/sample_app/app/models/user.rb:19: syntax error, unexpected tASSOC, expecting keyword_end
:length => { :maximum => 50 }
^
/Users/zkidd/Sites/rails_projects/sample_app/app/models/user.rb:23: syntax error, unexpected tASSOC, expecting $end
:format => { :with => email_regex },
^
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:454:in `load'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:454:in `block in load_file'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:591:in `new_constants_in'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:453:in `load_file'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:340:in `require_or_load'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:491:in `load_missing_constant'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:183:in `block in const_missing'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:181:in `each'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:181:in `const_missing'
from (irb):6
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.1/lib/rails/commands/console.rb:44:in `start'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.1/lib/rails/commands/console.rb:8:in `start'
from /Users/zkidd/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.1/lib/rails/commands.rb:23:in `<top (required)>'
from script/rails:6:in `require'
from …我已经学习了一个半星期的JS教程(Lynda.com和HeadFirst系列).事情很普遍,但JS对我来说并不像HTML/CSS那么容易.当我看到非常简单,初学者,代码(例如Lynda.com的教程,你创建一个宾果卡)时,我很难真正阅读代码中的逻辑参数表示.我的猜测是,如果我没有解决这个问题,那么我试图学习的任何其他语言都是不可能的,更不用说我不会很好地学习JS--或者根本就没有.
那么有人可以建议一个提供有关算法的基本指导的书籍/网站吗？ 或者,我只是太不耐烦了几个星期后,事情应该解决,代码会更有意义.
这是一个仍然预先准备的愚蠢基本代码示例.
function newCard() {
if (document.getElementById) {
for (var i=0; i<24; i++) {
setSquare(i);
}
我想了解算法所涉及的复杂范围.我认为对于像我这样的人来说,尝试更好地理解算法的制定方法以及如何解构它们将会很有趣和有用.
你能提供一个带解释的基本算法,一个带解释的中间算法,也许还有一个专家级别(有或没有)解释？