Question

我正在尝试将函数值存储在变量中，并希望在文本区域t1中显示内容。

因此，每次推送值时，我都可以在变量s中获取print函数，并可以在textarea t1中显示内容。

<html>
    <head>
        <title>Stack With Constructor </title>
    </head>
    <body>
        <div>Stack </div>
        <div>
            <h1>stack</h1>
            <h2>Stage1.</h2>
            <p id="p1">
                stack
            </p>
            <textarea id="t1"></textarea>
            <button onclick="doJob()">push</button>
            <button onclick="doJob1()">pop</button>
        </div>
        <textarea id="t"></textarea>
        <script>
            function push(v) {
                if (this.st === 0) {
                    console.log("Stack Overflow");
                } else {
                    this.st = this.st - 1;
                    this.stk[this.st] = v;
                }
            }

            function pop() {
                if (this.st === 10) {
                    console.log("Stack Underflow");
                } else {
                    var temp = this.stk[this.st];
                    this.st = this.st + 1;
                    return temp;
                }
            }

            function print() {
                console.log("Printing Stack");
                for (var i = this.st ; i < 10; i++) {
                    console.log(this.stk[i]);
                }
            };

            function MyStack() {
                this.st = 10;
                this.stk = new Array(10);
                this.push = push;
                this.pop = pop;
                this.print = print;
            };

            var s1 = new MyStack();

            function doJob() {
                var x=document.getElementById("t").value;
                s1.push(x);
                var s=s1.print();
                document.getElementById("t1").value=s;
            }
        </script>
    </body>
</html>

我想在文本区域t1中显示打印功能，以便它可以作为交互式堆栈。

当我尝试推送价值时，我在textarea中获得undefined。

Answer 1

更改您的打印功能，如

        function print() {
            console.log("Printing Stack");
            var str = "";//empty string
            for (var i = this.st ; i < 10; i++) {
                console.log(this.stk[i]);
                str+=this.stk[i]+'\n';//concatenate the value and a new line
            }
            return str;
        };

<强>样本

<html>
    <head>
        <title>Stack With Constructor </title>
    </head>
    <body>
        <div>Stack </div>
        <div>
            <h1>stack</h1>
            <h2>Stage1.</h2>
            <p id="p1">
                stack
            </p>
            <textarea id="t1"></textarea>
            <button onclick="doJob()">push</button>
            <button onclick="doJob1()">pop</button>
        </div>
        <textarea id="t"></textarea>
        <script>
            function push(v) {
                if (this.st === 0) {
                    console.log("Stack Overflow");
                } else {
                    this.st = this.st - 1;
                    this.stk[this.st] = v;
                }
            }

            function pop() {
                if (this.st === 10) {
                    console.log("Stack Underflow");
                } else {
                    var temp = this.stk[this.st];
                    this.st = this.st + 1;
                    return temp;
                }
            }

            function print() {
                console.log("Printing Stack");
                var str = "";//empty string
                for (var i = this.st ; i < 10; i++) {
                    console.log(this.stk[i]);
                    str+=this.stk[i]+'\n';//concatenate the value and a new line
                }
                return str;
            };

            function MyStack() {
                this.st = 10;
                this.stk = new Array(10);
                this.push = push;
                this.pop = pop;
                this.print = print;
            };

            var s1 = new MyStack();

            function doJob() {
                var x=document.getElementById("t").value;
                s1.push(x);
                var s=s1.print();
                document.getElementById("t1").value=s;
            }
            function doJob1(){
                s1.pop();
                var s=s1.print();
                document.getElementById("t1").value=s;                
            }
        </script>
    </body>

如何在变量中存储函数值并将其显示在textarea上

1 个答案: