When should I or should I not use the if without keys?

Asked

Viewed 2,860 times

4

I usually use always with keys because until today I do not know how exactly is the function of if without keys and if Else can also be without keys. Is there any variation in behavior between javascript and C#? and other languages?

Some examples that would confuse me whether or not they work:

Example 1:

if(true)
    variavel = 55;
else
    variavel = 100;

Example 2:

if(true)
    variavel1 = 55;
    variavel2 = 40;
else
    variavel1 = 100;
    variavel2 = 150;

Example 3

if (true)
   variavel1 = 55;
else{
   variavel1 = 100;
   variavel2 = 200;
}
javascript c#

  • Simply when the instruction you need to validate is done on a single line, after the first line what comes will not be within your if or Else. the ideal is always to use.

  • All these examples work (compile), may not do what you want. So always use keys.

1 answer

7


The IF without keys causes only the next expression to be evaluated.

In a variation of your example 2, 

if(variavel == true)
    variavel1 = 55;  //Será executado apenas se variavel == true;
    variavel2 = 40;  // Será executado incondicionalmente.

Incidentally, a better way to view the above code would be:

if(variavel == true)
    variavel1 = 55;

variavel2 = 40;

Realize that expression is different from line. The sequence below will behave exactly in the same way as in example 2:

if(variavel == true)
    variavel1 = 55; variavel2 = 40;
//                     ^- Execução incondicional
//     ^- Execução condicional

  • The explanation of the expression != line was essential to my understanding! I only continue with the doubt in relation to the Lse in these same cases.

Browser other questions tagged javascript c#

You are not signed in. Login or sign up in order to post.