boolean-logic

I want to write an if/else statement that tests if the value of a text input does NOT equal either one of two different values. Like this (excuse my pseudo-English code): var test = $("#test").val(); if (test does not equal A or B){ do stuff; } else { do other stuff; } How do I write the condition for the if statement on line 2? Think of ! (negation operator) as "not", || (boolean-or operator) as "or" and && (boolean-and operator) as "and". See Operators and Operator Precedence . Thus: if(!(a || b)) { // means neither a nor b } However, using De Morgan's Law , it could be written as: if(!a &&

I would like the element-wise logical OR operator. I know "or" itself is not what I am looking for. I am aware that AND corresponds to & and NOT, ~ . But what about OR? deinonychusaur The corresponding operator is | : df[(df < 3) | (df == 5)] would elementwise check if value is less than 3 or equal to 5. If you need a function to do this, we have np.logical_or . For two conditions, you can use df[np.logical_or(df<3, df==5)] Or, for multiple conditions use the logical_or.reduce , df[np.logical_or.reduce([df<3, df==5])] Since the conditions are specified as individual arguments, parentheses

Why TRUE == "TRUE" is TRUE in R? Is there any equivalent for === in R? Update: These are all returning FALSE : TRUE == "True" TRUE == "true" TRUE == "T" The only TRUE value is TRUE == "TRUE" . In case of checking with identical() everything works fine. Second Update: By === operator I meant the process of checking the Value and the Data Type of a variable . In this case I assumed that the == operator will only compare the Values of variables, not their Data Type as well. According to the help file ?`==` : If the two arguments are atomic vectors of different types, one is coerced to the type of

I'm reading Hadley Wickham's Advanced R section on coercion, and I can't understand the result of this comparison: "one" < 2 # [1] FALSE I'm assuming that R coerces 2 to a character, but I don't understand why R returns FALSE instead of returning an error. This is especially puzzling to me since -1 < "one" # TRUE So my question is two-fold: first, why this answer, and second, is there a way of seeing how R converts the individual elements within a logical vector like these examples? jdharrison From help("<") : If the two arguments are atomic vectors of different types, one is coerced to the