Skip to main content

prefer-string-starts-ends-with

Enforce using String#startsWith and String#endsWith over other equivalent methods of checking substrings.

🎨

在 ESLint 配置 中扩展"plugin:@typescript-eslint/stylistic-type-checked" 可启用此规则。

🔧

此规则报告的一些问题可通过 --fix ESLint 命令行选项自动修复。

💭

该规则需要 类型信息 才能运行。


有多种方法可以验证字符串是否以特定字符串开头或结尾，例如 foo.indexOf('bar') === 0。 截至 ES2015，JavaScript 中最常见的方式是使用 String#startsWith 和 String#endsWith。 始终坚持这些方法有助于提高代码的可读性。

英：There are multiple ways to verify if a string starts or ends with a specific string, such as foo.indexOf('bar') === 0. As of ES2015, the most common way in JavaScript is to use String#startsWith and String#endsWith. Keeping to those methods consistently helps with code readability.

此规则报告何时可以用 String#startsWith 或 String#endsWith 安全地替换字符串方法。

英：This rule reports when a string method can be replaced safely with String#startsWith or String#endsWith.

.eslintrc.cjs
module.exports = {
  "rules": {
    "@typescript-eslint/prefer-string-starts-ends-with": "error"
  }
};
在线运行试试这个规则 ↗

示例​

declare const foo: string;

// starts with
foo[0] === 'b';
foo.charAt(0) === 'b';
foo.indexOf('bar') === 0;
foo.slice(0, 3) === 'bar';
foo.substring(0, 3) === 'bar';
foo.match(/^bar/) != null;
/^bar/.test(foo);

// ends with
foo[foo.length - 1] === 'b';
foo.charAt(foo.length - 1) === 'b';
foo.lastIndexOf('bar') === foo.length - 3;
foo.slice(-3) === 'bar';
foo.substring(foo.length - 3) === 'bar';
foo.match(/bar$/) != null;
/bar$/.test(foo);
Open in Playground

何时不使用它​

如果你不介意使用哪种类型的字符串检查，则可以安全地关闭此规则。 但是，请记住，不一致的风格可能会损害项目的可读性。

英：If you don't mind which style of string checking is used, you can turn this rule off safely. However, keep in mind that inconsistent style can harm readability in a project.

选项​

该规则不可配置。

资源​