Search code examples
javascriptstringcomparison

Case insensitive string comparison in javascript

Can someone explain why this is the case?

console.log('AB_CD' > 'AB_C_D'); //false
console.log('ab_cd' > 'ab_c_d'); //true

Solution

  • Strings are compared using character codes, which you can learn more about reading this tutorial

    In this first comparison ('AB_CD' > 'AB_C_D'), the character code for D and _ are 68 and 95, respectively, which explains why the expression evaluates as false.

    A: 65; A: 65
B: 66; B: 66
_: 95; _: 95
C: 67; C: 67
D: 68; _: 95

    In the second comparison ('ab_cd' > 'ab_c_d'), the character code for d and _ are 100 and 95, respectively, which explains why the expression evaluates as true.

    a: 97;  a: 97
b: 98;  b: 98
_: 95;  _: 95
c: 99;  c: 99
d: 100; _: 95