Why does javascript if statement return true when string/numeric(nonzero) inputs are given as it's condition?

Question

I'm new to coding, and I wonder why the statement below gives true values.
Can someone give explanations for the logic?
When give numeric inputs, if the condition tests whether if it is a number, I think it should return true instead of false.
Thanks for helping out.

// Statement 1
if ("d") {
  reply = "TRUE!";
} else {
  reply = "FALSE?!";
}
console.log(reply)
// Returns "TRUE!"

// Statement 2
if (2) {
  reply = "TRUE!";
} else {
  reply = "FALSE?!";
}
console.log(reply)
// Also returns "TRUE!"

// Statement 3
if (0) {
  reply = "TRUE!";
} else {
  reply = "FALSE?!";
}
console.log(reply)
// Why does this return "FALSE?!"? I'm aware that 0 is false in boolean, but cannot understand how the syntax works considering statement 2.

Statement 3 runs after Statement 2, and Statement 3 assigns `FALSE` to the variable since it enters the `else`..? — CertainPerformance, Feb 10 '21 at 04:49
[This](https://developer.mozilla.org/en-US/docs/Glossary/Falsy) would help you better understanding — KcH, Feb 10 '21 at 04:49

score 0 · Accepted Answer · answered Feb 10 '21 at 05:07

0

Inputs that are not 0, null, underfined, NaN, or empty string will be judged as true

answered Feb 10 '21 at 05:07

红日初升

141
1
7

score 0 · Answer 2 · answered Feb 10 '21 at 05:12

0

Because 0 is the only number that equates to false. Other than that, statement two is equivalent to if(2==2)

answered Feb 10 '21 at 05:12

alec wilson

176
1
3
13

Why does javascript if statement return true when string/numeric(nonzero) inputs are given as it's condition?

2 Answers2