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charAtComparisons

Reports comparing charAt() results with strings longer than one character.

✅ This rule is included in the ts logical and logicalStrict presets.

The charAt method returns a string of exactly one character. If the return value is compared with a string of length greater than one, the comparison will always evaluate to the same result. Equality comparisons (===, ==) will always be false, and inequality comparisons (!==, !=) will always be true.

Examples

Section titled “Examples”
53teAB0char5<3(sp ansty="le--0:#F78C6C;--1:#AA09">8<20sp ansty="le--0:#D6DEEB;--1:#403F">53<) sp ansty="le--0:#C792EA;--1:#8844">AE=<==sp ansty="le--0:#D6DEEB;--1:#403F">5<3 sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4D1<1"sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco"><";d>1<1"sp ansty="le--0:#ECC48D;--1:#984E">4Da1<1"sp ansty="le--0:#D6DEEB;--1:#403F">5<3 sp ansty="le--0:#C792EA;--1:#8844">AE=<==sp ansty="le--0:#D6DEEB;--1:#403F">53 teAB0char5<3(sp ansty="le--0:#F78C6C;--1:#AA09">8<20sp ansty="le--0:#D6DEEB;--1:#403F">53<);d ivclassNa="meco"><);d>53teAB0char5<3(sp ansty="le--0:#F78C6C;--1:#AA09">8<20sp ansty="le--0:#D6DEEB;--1:#403F">53<) sp ansty="le--0:#C792EA;--1:#8844">AE!<==sp ansty="le--0:#D6DEEB;--1:#403F">5<3 sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4Dhel1<1"sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco"><";d>
3F534<4AE. spans="tyle--0:#82AAFF;--1:#3B">61B0ch30<9820 spans="tyle--0:#D6DEEB;--1:#40">3F<53) spans="tyle--0:#C792EA;--1:#88">44A31<111" spans="tyle--0:#ECC48D;--1:#98">41<111" spans="tyle--0:#D6DEEB;--1:#40">3<"a"><;di vdivclass="Nameexpressive-">3F534<4AE. spans="tyle--0:#82AAFF;--1:#3B">61B0s30<9820 spans="tyle--0:#D6DEEB;--1:#40">3F<53, spans="tyle--0:#F78C6C;--1:#AA">0<9822 spans="tyle--0:#D6DEEB;--1:#40">3F<53) spans="tyle--0:#C792EA;--1:#88">44A31<111" spans="tyle--0:#ECC48D;--1:#98">4E<4Dab spans="tyle--0:#D9F5DD;--1:#11">1<111" spans="tyle--0:#D6DEEB;--1:#40">3<;di vdivclass="Nameexpressive-">3F534<4AE. spans="tyle--0:#82AAFF;--1:#3B">61B0starts31<111" spans="tyle--0:#ECC48D;--1:#98">4E<4Dab spans="tyle--0:#D9F5DD;--1:#11">1<111" spans="tyle--0:#D6DEEB;--1:#40">3F<53) ;divclass="Name">

Options

Section titled “Options”

This rule is not configurable.

When Not To Use It

Section titled “When Not To Use It”

This rule catches a specific programming error with no legitimate use cases. There is no reason to disable this rule.

Further Reading

Section titled “Further Reading”

Equivalents in Other Linters

Section titled “Equivalents in Other Linters”