使用 Jquery 自动设置货币格式

如果需要，可以使用逗号和小数自动设置货币输入字段的格式。 文本会自动使用逗号进行格式化，并且光标会在格式化后放回到用户离开的位置，而光标会移动到输入的末尾。 验证在 KeyUp 上进行，最终验证在模糊上完成。

超文本标记语言

<input type="text" class="currency">

JavaScript

$(".currency").on({  
    keyup: function() {  
        let input_val = $(this).val();  
        input_val = numberToCurrency(input_val);  
        $(this).val(input_val);  
    },  
    blur: function() {   
        let input_val = $(this).val();  
        input_val = numberToCurrency(input_val, true, true);  
        $(this).val(input_val);  
    }  
});  
  
var numberToCurrency = function(input_val, fixed = false, blur = false) {  
    // don't validate empty input  
    if(!input_val) {  
        return "";  
    }  
      
    if(blur) {  
        if(input_val === "" || input_val == 0) { return 0; }  
    }  
  
    if(input_val.length == 1) {  
        return parseInt(input_val);  
    }  
  
    input_val = ''+input_val;  
      
    let negative = '';  
    if(input_val.substr(0, 1) == '-'){  
        negative = '-';  
    }  
    // check for decimal  
    if(input_val.indexOf(".") >= 0) {  
        // get position of first decimal  
        // this prevents multiple decimals from  
        // being entered  
        var decimal_pos = input_val.indexOf(".");  
  
        // split number by decimal point  
        var left_side = input_val.substring(0, decimal_pos);  
        var right_side = input_val.substring(decimal_pos);  
  
        // add commas to left side of number  
        left_side = left_side.replace(/\D/g, "").replace(/\B(?=(\d{3})+(?!\d))/g, ",");  
  
        if(fixed && right_side.length > 3) {  
            right_side = parseFloat(0+right_side).toFixed(2);  
            right_side =  right_side.substr(1, right_side.length);  
        }  
  
        // validate right side  
        right_side = right_side.replace(/\D/g, "").replace(/\B(?=(\d{3})+(?!\d))/g, ",");  
  
        // Limit decimal to only 2 digits  
        if(right_side.length > 2) {  
            right_side = right_side.substring(0, 2);  
        }  
      
        if(blur && parseInt(right_side) == 0) {  
            right_side = '';  
        }  
  
        // join number by.  
        // input_val = left_side + "." + right_side;  
  
        if(blur && right_side.length < 1) {  
            input_val = left_side;  
        } else {  
            input_val = left_side + "." + right_side;  
        }  
    } else {  
        // no decimal entered  
        // add commas to number  
        // remove all non-digits  
        input_val = input_val.replace(/\D/g, "").replace(/\B(?=(\d{3})+(?!\d))/g, ",");  
    }  
  
    if(input_val.length > 1 && input_val.substr(0, 1) == '0' && input_val.substr(0, 2) != '0.') {  
        input_val = input_val.substr(1, input_val.length);  
    } else if(input_val.substr(0, 2) == '0,') {  
        input_val = input_val.substr(2, input_val.length);  
    }  
      
    return negative+input_val;  
};