javascript-add-array-method

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Before1function findIndex(array, target) {
2    for (let i = 0; i < array.length; i++) {
3        if (array[i] === target) {
4            return i;
5        }
6    }
7    return -1;
8}
9
10const numbers = [1, 2, 3, 4, 5];
11const index = findIndex(numbers, 3);
12

After1function findIndex(array, target) {
2    return array.indexOf(target);
3}
4
5const numbers = [1, 2, 3, 4, 5];
6const index = findIndex(numbers, 3);
7

Before1function findIndex(array, target) {
2    for (let i = 0; i < array.length; i++) {
3        if (array[i] === target) {
4            return i;
5        }
6    }
7    return -1;
8}
9
10const numbers = [1, 2, 3, 4, 5];
11const index = findIndex(numbers, 3);
12

After1function findIndex(array, target) {
2    return array.indexOf(target);
3}
4
5const numbers = [1, 2, 3, 4, 5];
6const index = findIndex(numbers, 3);
7

Before1function findIndex(array, target) {
2    for (let i = 0; i < array.length; i++) {
3        if (array[i] === target) {
4            return i;
5        }
6    }
7    return -1;
8}
9
10const numbers = [1, 2, 3, 4, 5];
11const index = findIndex(numbers, 3);
12

After1function findIndex(array, target) {
2    return array.indexOf(target);
3}
4
5const numbers = [1, 2, 3, 4, 5];
6const index = findIndex(numbers, 3);
7

Before

program

function_declaration

function "function"

identifier "findIndex"

formal_parameters

( "("

identifier "array"

, ","

identifier "target"

) ")"

statement_block

{ "{"

for_statement

for "for"

( "("

lexical_declaration

let "let"

variable_declarator

identifier "i"

= "="

number "0"

; ";"

binary_expression

identifier "i"

< "<"

member_expression

identifier "array"

. "."

property_identifier "length"

; ";"

update_expression

identifier "i"

++ "++"

) ")"

statement_block

{ "{"

if_statement

if "if"

parenthesized_expression

( "("

binary_expression

subscript_expression

identifier "array"

[ "["

identifier "i"

] "]"

=== "==="

identifier "target"

) ")"

statement_block

{ "{"

return_statement

return "return"

identifier "i"

; ";"

} "}"

return_statement

return "return"

unary_expression

- "-"

number "1"

; ";"

} "}"

lexical_declaration

const "const"

variable_declarator

identifier "numbers"

= "="

array

[ "["

number "1"

, ","

number "2"

, ","

number "3"

, ","

number "4"

, ","

number "5"

] "]"

; ";"

lexical_declaration

const "const"

variable_declarator

identifier "index"

= "="

call_expression

identifier "findIndex"

arguments

( "("

identifier "numbers"

, ","

number "3"

) ")"

; ";"

After

program

function_declaration

function "function"

identifier "findIndex"

formal_parameters

( "("

identifier "array"

, ","

identifier "target"

) ")"

statement_block

{ "{"

return_statement

return "return"

call_expression

member_expression

identifier "array"

. "."

property_identifier "indexOf"

arguments

( "("

identifier "target"

) ")"

; ";"

} "}"

lexical_declaration

const "const"

variable_declarator

identifier "numbers"

= "="

array

[ "["

number "1"

, ","

number "2"

, ","

number "3"

, ","

number "4"

, ","

number "5"

] "]"

; ";"

lexical_declaration

const "const"

variable_declarator

identifier "index"

= "="

call_expression

identifier "findIndex"

arguments

( "("

identifier "numbers"

, ","

number "3"

) ")"

; ";"

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