noVar

诊断类别：lint/style/noVar

¥Diagnostic Category: lint/style/noVar

JavaScript (and super languages)

自从：v1.0.0

¥Since: v1.0.0

来源：

¥Sources:

与以下相同：no-var

¥Same as: no-var

禁止使用 var

¥Disallow the use of var

ECMAScript 6 允许程序员使用 let 和 const 关键字创建具有块作用域而不是函数作用域的变量。

¥ECMAScript 6 allows programmers to create variables with block scope instead of function scope using the let and const keywords.

块范围在许多其他编程语言中很常见，可辅助程序员避免错误。

¥Block scope is common in many other programming languages and helps programmers avoid mistakes.

示例

¥Examples

无效

¥Invalid

var foo = 1;

code-block.js:1:1 lint/style/noVar  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Use let or const instead of var.
  
  > 1 │ var foo = 1;
      │ ^^^^^^^^^^^
    2 │ 
  
  ℹ A variable declared with var is accessible in the whole module. Thus, the variable can be accessed before its initialization and outside the block where it is declared.
  
  ℹ See MDN web docs for more details.
  
  ℹ Unsafe fix: Use ‘const’ instead.
  
    1   │ - var·foo·=·1;
      1 │ + const·foo·=·1;
    2 2 │

有效

¥Valid

const foo = 1;
let bar = 1;

noVar

示例

无效

有效

相关链接