Javascript 数组变量在循环中丢失

Question

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Answer 1

我认为这是经典的闭包问题，希望可以在这里得到解释:JavaScript closure inside loops – simple practical example

将所有内容包装在 for 循环中:

(function (colNum) {
    // Your code in the for loop
})(col_id[i]);

并删除你的 var colNum = col_id[i]; 行

所以最终的代码看起来是这样的:

(function() {
    tinymce.create('tinymce.plugins.col', {
        init : function(ed, url) {
            var col_id = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'eleven'];
            for(var i = 0; i < col_id.length; i++){
                (function (colNum) {    // <---------------------- ADDED THIS
                    ed.addButton(colNum+'_col', {
                        title : colNum+' Column',
                        image : url+'/images/mce/'+colNum+'.png',
                        onclick : function() {
                            ed.selection.setContent('['+colNum+'_col]' + ed.selection.getContent() + '[/'+colNum+'_col]');

                        }
                    }); // ***** Col *****

                    ed.addButton(colNum+'_col_first', {
                        title : colNum+' Column First',
                        image : url+'/images/mce/'+colNum+'.png',
                        onclick : function() {
                            ed.selection.setContent('['+colNum+'_col_first]' + ed.selection.getContent() + '[/'+colNum+'_col_first]');

                        }
                    });  // ******  Col First ******

                    ed.addButton(colNum+'_col_last', {
                        title : colNum+' Column Last',
                        image : url+'/images/mce/'+colNum+'.png',
                        onclick : function() {
                            ed.selection.setContent('['+colNum+'_col_last]' + ed.selection.getContent() + '[/'+colNum+'_col_last]');

                        }
                    });   //*********  Col Last **********
                })(col_id[i]);    // <------------------------- ADDED THIS
            }
        },
        createControl : function(n, cm) {
            return null;
        }
    });
    tinymce.PluginManager.add('col', tinymce.plugins.col);
})();