实用Javascript代码片段

清除select下拉选项，添加并选择特点选项

$('#mySelect')
    .find('option')
    .remove()
    .end()
    .append('<option value="whatever">text</option>')
    .val('whatever')
;

ref:http://stackoverflow.com/questions/47824/how-do-you-remove-all-the-options-of-a-select-box-and-then-add-one-option-and-se

为字符串添加endsWith的方法

String.prototype.endsWith = function(suffix) {
    return this.indexOf(suffix, this.length - suffix.length) !== -1;
};

ref :http://stackoverflow.com/questions/280634/endswith-in-javascript

同理，字符串startsWith方法

if (typeof String.prototype.startsWith != 'function') {
  // see below for better implementation!
  String.prototype.startsWith = function (str){
    return this.indexOf(str) === 0;
  };
}

ref : http://stackoverflow.com/questions/646628/how-to-check-if-a-string-startswith-another-string

为数组添加remove方法

// Array Remove - By John Resig (MIT Licensed)
Array.prototype.remove = function(from, to) {
  var rest = this.slice((to || from) + 1 || this.length);
  this.length = from < 0 ? this.length + from : from;
  return this.push.apply(this, rest);
};

ref: http://ejohn.org/blog/javascript-array-remove/#postcomment

判断HTML元素是否有子元素

if ( $('#myfav').children().size() > 0 ) {
     // do something
}

or

if ($('#myfav').is(':parent')) {
    // do something
}

ref:http://stackoverflow.com/questions/1526873/jquery-if-div-id-has-children

转载于:https://www.cnblogs.com/flowerszhong/p/4477762.html