Assign x

Category:Variables

Assign a value to a variable

Category: Variables

Assigns a value to a previously declared variable.

To process data in our apps we need to assign values to memory locations we have previously named using var to declare a variable. Programmers read the statement "area = length * width;" as "area gets length times width". The variable getting the value always goes on the left hand side of the assignment operator =. The right hand side of the assignment operator can be a number or a string, or the number or string returned by a function, or the numeric or string result of the evaluation of an expression.

Examples

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// Declare, assign, and output the value of a variable.
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var x;
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x = 5;
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console.log("x has the value " + x)

Example: Circumference and Area Calculate the circumference and area of a circle with radius 10.

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// Calculate the circumference and area of a circle with radius 10.
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var radius, circumference, area;
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radius = 10;
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circumference = 2 * Math.PI * radius;
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area = Math.PI * radius * radius;
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console.log("Circle radius 10 has circumference of " + circumference + " and area of " + area);

Example: Fibonacci Generate the first nine terms of the Fibonacci series.

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// Generate the first 9 terms of the Fibonacci series.
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var termA, termB, termC;
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termA = 1;
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termB = 1;
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termC = termA + termB;
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console.log(termA + " " + termB + " " + termC);
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termA = termB + termC;
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termB = termC + termA;
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termC = termA + termB;
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console.log(termA + " " + termB + " " + termC);
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termA = termB + termC;
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termB = termC + termA;
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termC = termA + termB;
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console.log(termA + " " + termB + " " + termC);

Example: Message Board Collect, count and display messages from friends.

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// Collect, count and display messages from friends.
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textLabel("myTextLabel", "Type a message and press press enter");
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textInput("myTextInput", "");
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var count;
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count=1;
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onEvent("myTextInput", "change", function(event) {
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  var myText;
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  myText = getText("myTextInput");
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  write("Message #" + count + ": " + myText);
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  setText("myTextInput", "");
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  count = count + 1;
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});

Syntax

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x = ___;

Parameters

Name Type Required? Description
x variable name Yes The name you will use in the program to reference the variable. Must begin with a letter, contain no spaces, and may contain letters, digits, - and _.
___ any type Yes The right hand side of the assignment operator can be a number or a string, or the number or string returned by a function, or the numeric or string result of the evaluation of an expression.

Returns

No return value. Variable assigned value in memory.

Tips

  • The variable must be declared using var before it can be assigned its initial value.
  • You can use the same variable on both the right hand side of the assignment operator = and the left hand side. This is sometimes used for a counter count = count + 1;
  • = is the assignment operator. == is the boolean check for equivalency operator.

Found a bug in the documentation? Let us know at documentation@code.org

Syntax

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x = __;

Returns

Does not return a value. Assigns 2 to someVal. Assumes that someVal has already been declared.

Found a bug in the documentation? Let us know at documentation@code.org