Javascript 仅用于假表达式的三元条件运算符

Question

I have just learned how to use Javascript ternary conditional operator.

condition ? true : false

The question is i want to use the operator with only false expression.

what i expect

condition : false expression

but above code not work, is there any way?

Answer 1

Javascript ternary conditional operator for only false expression

This is not possible. You don't even need to know ECMAScript or TypeScript to know that this is not possible, just basic English: the word " ternary " means "composed of three things", so a ternary conditional operator can by definition only have the condition and two consequences.

If it only had a condition and one consequence, it would be a binary conditional operator.

Answer 2

Please see this Ternary Operator . It clearly says ternary operator has three parts.

1. Condition
2. Value if true
3. value if false

So you cannot do as you asked. Instead you should use simple if and check if condition is false and return false value.

Answer 3

condition || expression

can use like

form.isValid || form.submit()

The form's submit method will not be evaluated if the isValid property is falsey.