Introduction to Truthy and Falsy in JavaScript _javascript tips

As with most programming languages, there is a Boolean type in JavaScript that is used logically for judgment. However, unlike many other programming languages, the concept of truthy values and Falsy values exists in JavaScript-all types of JavaScript values, except Boolean true and False, can be used for logical judgments, with the following rules:

1. All falsy values are false when making logical judgments. Falsy values include: false, Undefined, null, plus or minus 0, NaN, "".
2. All remaining values are truthy, true when making logical judgements. It is noteworthy that Infinity, empty array, "0″ are all truthy values."

Experiment

Copy Code code as follows:

var x = "0";
if (x) {
"String 0 is truthy."
} else {
"String 0 is Falsy."
}

var y = [];
if (y) {
"Empty array is truthy."
} else {
"Empty array is falsy."
}