取中间文本

get-middle-string.js

export function getMiddleString(src = '', left = '', right = '', more = false) {
    let leftIndex = src.indexOf(left)
    if (leftIndex === -1) {
        return ''
    }

    leftIndex += left.length
    let rightIndex
    if (more) {
        rightIndex = src.lastIndexOf(right, leftIndex)
    } else {
        rightIndex = src.indexOf(right, leftIndex)
    }
    if (rightIndex === -1) {
        return ''
    }

    return src.slice(leftIndex, rightIndex)
}

get-middle-string.test.js

import { getMiddleString } from './get-middle-string.js'

// get middle
getMiddleString('[hello][world]', '[', ']') // hello

// get more middle
getMiddleString('[hello][world]', '[', ']', true) // hello][world