ReferenceError: "x" is not defined

    ReferenceError: "x" is not defined

?

. . , scope .

: ( jQuery ) , "$" . <script> .

foo.substring(1); // ReferenceError: foo is not defined

var foo = "bar";
foo.substring(1); // "ar"

. . , .

function numbers() {
  var num1 = 2,
    num2 = 3;
  return num1 + num2;
}

console.log(num1); // ReferenceError: num1 is not defined

, . , .

var num1 = 2,
  num2 = 3;

function numbers() {
  return num1 + num2;
}

console.log(num1); // 2

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This page was last modified on 2024 12 17 by MDN contributors.