Node.js - 没有检测到相同的数据

Question

I'm comparing two strings I get from the SQL database and the html form but the equals don't work.

    if (database.recordset[0].name=== myString) {
          console.log("work");
    }else{
          console.log("dont work");
    }         

OUTPUT

dont work

Read data with console

console.log(database.recordset[0].name);
console.log(myString);

OUTPUT:

asdasd
asdasd

But if not working...

EDIT

I used this:

 console.log(typeof database.recordset[0].name);
 console.log(typeof myString);

OUTPUT

  string
  string

Answer 1

When comparing MySQL and other variables the main difference between "==" and "===" operator is that formerly compares variable by making type correction eg if you compare a number with a string with numeric literal, == allows that, but === doesn't allow that, because it not only checks the value but also type of two variable, if two variables are not of the same type "===" return false, while "==" return true.

<script> 
// In R.H.S. string "3" is converted into 
// number 3, hence returns true. 
document.write(9 == "9");  

// used for next line 
document.write('<br>') 

// Here no type conversion takes place, 
// hence returns false 
document.write(9 === "9");  

here is another example with strings

 // Here LHS is a string literal whereas // RHS is a string object, // due to type conversion of string object into // a string literal, it returns true. document.write("GeeksforGeeks" == new String("GeeksforGeeks")); // used for next line document.write('<br>') // No type conversion takes place document.write("GeeksforGeeks" === new String("GeeksforGeeks"));