js日常開發3

// 深拷貝(可拷貝對象或數組)(推薦)
function extend(source) {
let sourceCopy = source.constructor === Array ? [] : {};
for (let keys in source) {
if (source.hasOwnProperty(keys)) {
if (source[keys] && typeof source[keys] === ‘object’) {
sourceCopy[keys] = source[keys].constructor === Array ? [] : {};
sourceCopy[keys] = extend(source[keys]);
} else {
sourceCopy[keys] = source[keys];
}
}
}
return sourceCopy;
}
// 數組深拷貝
function copyArr(arr) {
if (arr === ” || arr === null || arr === undefined) { return; }
return arr.map((e) => {
if (typeof e === ‘object’) {
return Object.assign({}, e);
} else {
return e;
}
});
}

/**
* @desc 獲取當前光標位置
* @param {dom} [element] dom元素
* @return {number} 光標位置
*/
function getCursortPosition(element) {
let caretPos = 0;
if (document.selection) {
element.focus();
let Sel = document.selection.createRange();
Sel.moveStart(‘character’, -element.value.length);
caretPos = Sel.text.length;
} else if (element.selectionStart || element.selectionStart === ‘0’) {
caretPos = element.selectionStart;
}
return caretPos;
}
/**
* @desc 設置光標位置
* @param {dom} [element] dom元素
* @param {Number} [pos] 光標位置
*/
function setCaretPosition(element, pos) {
if (element.setSelectionRange) {
element.focus();
element.setSelectionRange(pos, pos);
} else if (element.createTextRange) {
let range = element.createTextRange();
range.collapse(true);
range.moveEnd(‘character’, pos);
range.moveStart(‘character’, pos);
range.select();
}
}