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no-else-return

Disallow else blocks after return statements in if statements

🔧

Some problems reported by this rule are automatically fixable by the --fix command line option

If an if block contains a return statement, the else block becomes unnecessary. Its contents can be placed outside of the block.

function foo() {
    if (x) {
        return y;
    } else {
        return z;
    }
}

Rule Details

This rule is aimed at highlighting an unnecessary block of code following an if containing a return statement. As such, it will warn when it encounters an else following a chain of ifs, all of them containing a return statement.

Options

This rule has an object option:

  • allowElseIf: true (default) allows else if blocks after a return
  • allowElseIf: false disallows else if blocks after a return

allowElseIf: true

Examples of incorrect code for this rule:

/*eslint no-else-return: "error"*/

function foo() {
    if (x) {
        return y;
    } else {
        return z;
    }
}

function foo() {
    if (x) {
        return y;
    } else if (z) {
        return w;
    } else {
        return t;
    }
}

function foo() {
    if (x) {
        return y;
    } else {
        var t = "foo";
    }

    return t;
}

function foo() {
    if (error) {
        return 'It failed';
    } else {
        if (loading) {
            return "It's still loading";
        }
    }
}

// Two warnings for nested occurrences
function foo() {
    if (x) {
        if (y) {
            return y;
        } else {
            return x;
        }
    } else {
        return z;
    }
}

Examples of correct code for this rule:

/*eslint no-else-return: "error"*/

function foo() {
    if (x) {
        return y;
    }

    return z;
}

function foo() {
    if (x) {
        return y;
    } else if (z) {
        var t = "foo";
    } else {
        return w;
    }
}

function foo() {
    if (x) {
        if (z) {
            return y;
        }
    } else {
        return z;
    }
}

function foo() {
    if (error) {
        return 'It failed';
    } else if (loading) {
        return "It's still loading";
    }
}

allowElseIf: false

Examples of incorrect code for this rule:

/*eslint no-else-return: ["error", {allowElseIf: false}]*/

function foo() {
    if (error) {
        return 'It failed';
    } else if (loading) {
        return "It's still loading";
    }
}

Examples of correct code for this rule:

/*eslint no-else-return: ["error", {allowElseIf: false}]*/

function foo() {
    if (error) {
        return 'It failed';
    }

    if (loading) {
        return "It's still loading";
    }
}

Version

This rule was introduced in ESLint v0.0.9.

Resources

© OpenJS Foundation and other contributors
Licensed under the MIT License.
https://eslint.org/docs/latest/rules/no-else-return